WO2023115639A1 - Molecular crystal energy calculation method and apparatus and storage medium - Google Patents

Abstract

A molecular crystal energy calculation method and apparatus and a storage medium. The method comprises: obtaining a target crystal structure, and determining a central molecule, M clusters, and M shell structures from the target crystal structure (S110); separately calculating the molecular energy of the central molecule, the cluster energy of each cluster and the shell energy of each shell structure by using a quantum chemistry method (S120); calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy (S130); and calculating the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy (S140). According to the technical solution, the calculation efficiency and the calculation precision of the crystal energy can be improved by establishing a "shell-core" calculation solution.

Description

A molecular crystal energy calculation method, device and storage medium

This application claims the priority of the Chinese patent application submitted to the State Intellectual Property Office on December 24, 2021, with the application number 202111600787.1 and the application name "A method, device and storage medium for molecular crystal energy calculation". References are incorporated in this application.

technical field

The application belongs to the technical field of molecular crystals, and in particular relates to a molecular crystal energy calculation method, device and storage medium.

Background technique

Molecular crystal is a kind of structure formed by stacking of organic molecules through weak non-bonding interactions. Accurate description of weak interactions usually requires high-precision methods with extremely high algorithm complexity, and such methods are usually difficult to apply to large molecular crystal systems. Molecular crystal calculations usually choose the cheaper density functional theory method, semi-empirical method or empirical force field method. In order to be able to apply high-precision methods to molecular crystals, people usually decompose the total energy of the crystal into the sum of several subsystems.

Existing calculation schemes usually need to extract a large number of cluster structures from crystals according to specific rules to perform two-body, three-body, and even four-body calculations. Usually, with the increase in accuracy and the consideration of many-body effects, The size and number of clusters increase rapidly, which makes the final calculation process complicated and costly.

Due to the limitation of computing resources, existing computing schemes usually discard clusters with smaller contributions according to certain rules, which may introduce certain errors. Moreover, in order to introduce the overall effect of the crystal, the existing scheme usually uses a low-precision method to calculate the energy of the crystal, which also introduces a certain error.

technical problem

In order to solve or partially solve the problems existing in related technologies, this application provides a molecular crystal energy calculation method, device and storage medium. By establishing a "core-shell" calculation scheme, the calculation efficiency and calculation accuracy of crystal energy can be improved.

technical solution

The first aspect of the present application provides a molecular crystal energy calculation method, including:

Obtain the target crystal structure, and determine the central molecule, M clusters and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

Calculating the molecular energy of the central molecule, the cluster energy of each of the clusters, and the shell energy of each of the shell structures using quantum chemical methods;

calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy;

According to the molecular energy and the lattice energy, the total crystal energy of the target crystal structure is calculated.

Preferably, the determination of the central molecule, M clusters and M shell structures from the target crystal structure includes:

selecting a molecule from the target crystal structure as the central molecule;

Take the geometric center of the central molecule as the center of the sphere, and use M different preset radii as cut-off radii to carry out atomic interception on the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M said clusters;

The central molecule is deleted from each of the clusters to obtain the corresponding M shell structures.

Preferably, the selected atoms are located within the molecular cut-off radius to construct clusters, including:

selecting molecules with all atoms within the cut-off radius to construct clusters; or,

If only some atoms of a molecule are located within the cutoff radius, the molecules are completed, and the completed molecules and molecules with all atoms located within the cutoff radius are used to construct clusters.

Preferably, the calculation of the molecular energy of the central molecule, the cluster energy of each of the clusters and the shell energy of each of the shell structures using quantum chemical methods includes:

Using the molecular structure of the central molecule as an input, calculating the molecular energy of the central molecule and the sub-energies that constitute the molecular energy by using quantum chemical methods;

Using the structure of each of the clusters as an input, the quantum chemical method is used to calculate the cluster energy of each of the clusters and the component energies that constitute the cluster energy;

Each of the shell structures is used as an input, and the quantum chemical method is used to calculate the shell energy of each shell structure and the component energies constituting the shell energy.

Preferably, the quantum chemical method includes a tight-binding DFTB method based on density functional theory, and the energy calculation formula is:

E _energy = E _{0 approx} + E _scc + E _rep + E _nuc + E _{disp_corr} ;

Among them, the sub-item energies E _{0 approximation} , E _scc , E _rep , _Enuc , and E _{disp_corr} are: orbital energy under zero-order approximation, second/third-order electrostatic energy, short-range repulsion energy of valence bonds, and nuclear repulsion energy , the long-range dispersion correction energy.

Preferably, the quantum chemical method includes a density functional theory DFT method, and the energy calculation formula is:

E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ;

Among them, the sub-items of energy E ₀ , E _j , _Ex , E _c , _Enuc , and E _{disp_corr} are: orbital energy, electron electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, and long-range dispersion correction energy.

Preferably, the calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy includes:

According to the partial energies of the molecular energy, the partial energies of each of the cluster energies, and the partial energies of each of the shell energies, the relationship between the central molecule and each - Partial energies of the interaction energy between said shell structures;

According to the sub-items of the interaction energy between the central molecule and each of the shell structures, the sub-items of the lattice energy of the target crystal structure are calculated using a second preset formula;

According to the component energies of the lattice energy and the contribution coefficients of the component energies, the lattice energy of the target crystal structure is calculated using a third preset formula.

Preferably, the first preset formula is:

E _{shell n interaction energy, i} = E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ;

Wherein, the n is the cluster number, the value of n is 1-M, the i is the number of each sub-item energy, and the E _{cluster n,i} is the cluster energy of the nth cluster The i-th partial energy of the E _{molecule, i} is the i-th partial energy of the molecular energy of the central molecule, and the E _{shell n,i} is the i-th shell energy of the n-th shell structure Subitem energy, the E _{shell n interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the nth shell structure.

Preferably, when the M is greater than or equal to 3, the second preset formula is:

E _{shell n interaction energy. i} = E _{lattice, i} +A*(R _n ) ^-B ;

Wherein, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, the R _n is the intercept radius adopted when constructing the n-th cluster, and the A and The B is two different attenuation coefficients;

The sub-items of the interaction energy between the central molecule and each of the shell structures are calculated using a second preset formula to obtain the sub-items of the lattice energy of the target crystal structure, including :

calculating the partial energies of the interaction energy between the central molecule and each of the shell structures using the second preset formula to obtain multiple sets of the E _lattice,i , A and B;

Fitting multiple sets of _{lattice E,i} , A, and B to obtain subitem energies of lattice energies of the target crystal structure.

Preferably, when the M is 2, the second preset formula is:

E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ];

Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the interaction between the central molecule and the first shell structure The i-th sub-item energy of the action energy, the E _{-shell 2 interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, and the _R1 is the construction of the first sub-item energy The cut-off radius used when 1 cluster is used, and the _R2 is the cut-off radius used when constructing the second cluster.

Preferably, when the M is 1, the n is 1, and the second preset formula is:

E _{lattice, i} = E _{shell 1 interaction energy, i} ;

Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the interaction energy between the central molecule and the shell structure The energy of the i-th component.

Preferably, the third preset formula is:

E _lattice = sum(k _i E _{lattice, i} );

Wherein, the E _lattice is the lattice energy of the target crystal structure, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, and the _ki is the The contribution coefficient of the i-th component energy of the lattice energy.

Preferably, the calculation method of the contribution coefficient of each sub-item energy of the lattice energy includes:

obtaining a plurality of reference crystal structures and sub-energies of reference lattice energies for each of said reference crystal structures;

separately calculating the partial energies of the lattice energies of each said reference crystal structure;

Setting the contribution coefficient of each component energy of the lattice energy;

Obtaining the sub-items of the predicted lattice energy of each of the reference crystal structures according to the sub-items of the lattice energy of each of the reference crystal structures and the set contribution coefficient;

Using the sub-items of the reference lattice energy and the sub-items of the predicted lattice energy of each of the reference crystal structures, fitting the set contribution coefficients to obtain the fitting contribution of each sub-item energy coefficient.

Preferably, the total crystal energy of the target crystal structure is calculated according to the molecular energy and the lattice energy, including:

performing energy correction on the molecular energy to obtain the corrected molecular energy;

Using the corrected molecular energy and the lattice energy, the total crystal energy of the target crystal structure is calculated.

The second aspect of the present application provides a molecular crystal energy comparison method, including:

obtaining at least two crystal structures to be compared;

Using the molecular crystal energy calculation method as provided in the first aspect of the present application to perform crystal energy calculation for each of the crystal structures, to obtain the total crystal energy of each of the crystal structures;

According to the total crystal energy of each of the crystal structures, the magnitude relationship of the crystal energies of the at least two crystal structures is determined.

The third aspect of the present application provides a molecular crystal energy calculation device, including:

An acquisition module, configured to acquire a target crystal structure, and determine the central molecule, M clusters and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

The first calculation module is used to separately calculate the molecular energy of the central molecule, the cluster energy of each of the clusters and the shell energy of each of the shell structures by using a quantum chemical method;

A second calculation module, configured to calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy;

The third calculation module is used to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

Preferably, the acquisition module determines the central molecule, M clusters and M shell structures from the target crystal structure, including:

selecting a molecule from the target crystal structure as the central molecule;

Take the geometric center of the central molecule as the center of the sphere, and use M different preset radii as cut-off radii to carry out atomic interception on the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M said clusters;

The central molecule is deleted from each of the clusters to obtain the corresponding M shell structures.

Preferably, the acquisition module selects molecules whose atoms are located within the cut-off radius to construct clusters, including:

selecting molecules with all atoms within the cut-off radius to construct clusters; or,

If only some atoms of a molecule are located within the cutoff radius, the molecules are completed, and the completed molecules and molecules with all atoms located within the cutoff radius are used to construct clusters.

Preferably, the first calculation module includes:

The first calculation unit is used to use the molecular structure of the central molecule as an input, and calculate the molecular energy of the central molecule and the sub-energy of the molecular energy by using quantum chemical methods;

The second calculation unit is used to use the structure of each cluster as an input to calculate the cluster energy of each cluster and the energy of each subitem of the cluster energy by using a quantum chemical method;

The third calculation unit is used to use each shell structure as an input to calculate the shell energy of each shell structure and the component energies constituting the shell energy by quantum chemical method.

Preferably, the quantum chemical method includes a tight-binding DFTB method based on density functional theory, and the energy calculation formula is:

E _energy = E _{0 approx} + E _scc + E _rep + E _nuc + E _{disp_corr} ;

Among them, the sub-item energies E _{0 approximation} , E _scc , E _rep , _Enuc , and E _{disp_corr} are: orbital energy under zero-order approximation, second/third-order electrostatic energy, short-range repulsion energy of valence bonds, and nuclear repulsion energy , the long-range dispersion correction energy.

Preferably, the quantum chemical method includes a density functional theory DFT method, and the energy calculation formula is:

E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ;

Among them, the sub-items of energy E ₀ , E _j , _Ex , E _c , _Enuc , and E _{disp_corr} are: orbital energy, electron electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, and long-range dispersion correction energy.

Preferably, the second calculation module includes:

The fourth calculation unit is used to calculate using the first preset formula according to the sub-items of the molecular energy, the sub-items of each of the cluster energies, and the sub-items of each of the shell energies obtaining the partial energies of the interaction energy between the central molecule and each of the shell structures;

The fifth calculation unit is used to calculate and obtain the lattice energy of the target crystal structure according to the component energies of the interaction energy between the central molecule and each of the shell structures by using the second preset formula. itemized energy;

The sixth calculation unit is configured to calculate the lattice energy of the target crystal structure by using a third preset formula according to the component energies of the lattice energy and the contribution coefficients of the component energies.

Preferably, the first preset formula is:

E _{shell n interaction energy, i} = E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ;

Wherein, the n is the cluster number, the value of n is 1-M, the i is the number of each sub-item energy, and the E _{cluster n,i} is the cluster energy of the nth cluster The i-th partial energy of the E _{molecule, i} is the i-th partial energy of the molecular energy of the central molecule, and the E _{shell n,i} is the i-th shell energy of the n-th shell structure Subitem energy, the E _{shell n interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the nth shell structure.

Preferably, when the M is greater than or equal to 3, the second preset formula is:

E _{shell n interaction energy. i} = E _{lattice, i} +A*(R _n ) ^-B ;

Wherein, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, the R _n is the intercept radius adopted when constructing the n-th cluster, and the A and The B is two different attenuation coefficients;

The fifth calculation unit is specifically used to calculate the component energies of the interaction energy between the central molecule and each of the shell structures using the second preset formula to obtain multiple sets of E _{crystals Lattice, i} , A and B; multiple sets of E _{lattice, i} , A and B are fitted to obtain the sub-item energy of the lattice energy of the target crystal structure.

Preferably, when the M is 2, the second preset formula is:

E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ];

Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the distance between the central molecule and the first shell structure The i-th sub-item energy of the interaction energy, the E _{-shell 2 interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, the R ₁ is the cut-off radius used when constructing the first cluster, and R ₂ is the cut-off radius used when constructing the second cluster.

Preferably, when the M is 1, the n is 1, and the second preset formula is:

E _{lattice, i} = E _{shell 1 interaction energy, i} ;

Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the interaction between the central molecule and the shell structure energy of the i-th component of energy.

Preferably, the third preset formula is:

E _lattice = sum(k _i E _{lattice, i} );

Wherein, the E _lattice is the lattice energy of the target crystal structure, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, and the _ki is the The contribution coefficient of the i-th component energy of the lattice energy.

Preferably, the sixth calculation unit calculates the contribution coefficient of each sub-item energy of the lattice energy, including:

obtaining a plurality of reference crystal structures and reference lattice energies for each of said reference crystal structures;

separately calculating the partial energies of the lattice energies of each said reference crystal structure;

Setting the contribution coefficient of each component energy of the lattice energy;

Obtaining the sub-items of the predicted lattice energy of each of the reference crystal structures according to the sub-items of the lattice energy of each of the reference crystal structures and the set contribution coefficient;

Using the sub-items of the reference lattice energy and the sub-items of the predicted lattice energy of each of the reference crystal structures, fitting the set contribution coefficients to obtain the fitting contribution of each sub-item energy coefficient.

Preferably, the third calculation module includes:

a calibration unit, configured to perform energy calibration on the molecular energy to obtain the corrected molecular energy;

A seventh calculation unit, configured to calculate the total crystal energy of the target crystal structure by using the corrected molecular energy and the lattice energy.

The fourth aspect of the present application provides a molecular crystal energy comparison device, including:

an acquisition module, configured to acquire at least two crystal structures to be compared;

A calculation module, configured to use the molecular crystal energy calculation device provided in the third aspect of the present application to calculate the crystal energy of each of the crystal structures, and obtain the total crystal energy of each of the crystal structures;

The determination module is configured to determine the relationship between the crystal energies of the at least two crystal structures according to the total crystal energy of each of the crystal structures.

The fifth aspect of the present application provides an electronic device, including:

processor; and

A memory on which executable codes are stored, and when the executable codes are executed by the processor, the processor is made to execute the molecular crystal energy calculation method provided in the first aspect of the present application or the method described in the first aspect of the present application The energy comparison method of the molecular crystal provided in the second aspect.

The sixth aspect of the present application provides a computer-readable storage medium, on which executable code is stored, and when the executable code is executed by the processor of the electronic device, the processor executes the method provided in the first aspect of the present application. The molecular crystal energy calculation method or the molecular crystal energy comparison method provided in the second aspect of the present application.

Beneficial effect

In the technical solution provided by this application, after obtaining the target crystal structure, the central molecule, at least one cluster structure and the corresponding shell structure can be determined from it, and the molecular energy of the central molecule, the The cluster energy of the structure and the shell energy of each shell structure are calculated based on the above energies to obtain the lattice energy of the target crystal structure, and then the molecular energy of the central molecule and the lattice energy are used to calculate the total crystal energy of the target crystal structure. This application establishes a "core-shell" calculation scheme by calculating the energy of the central molecule (core) and cluster (shell), which can avoid the calculation of a large number of two-body, three-body and other multi-body clusters in the prior art, and can obtain Compared with the original direct low-precision calculation method, the energy accuracy is higher, and the calculation efficiency is also greatly improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Description of drawings

The above and other objects, features and advantages of the present application will become more apparent by describing the exemplary embodiments of the present application in more detail with reference to the accompanying drawings, wherein, in the exemplary embodiments of the present application, the same reference numerals generally represent same parts.

Fig. 1 is a schematic flow chart of a molecular crystal energy calculation method provided in the embodiment of the present application;

Fig. 2 is the central molecular structure diagram in a kind of Aspirin crystal provided by the embodiment of the present application;

Fig. 3 is the center molecule in Fig. 2 as the center of the sphere, with R ₁ as the molecular structure diagram after the cut-off radius is carried out;

Fig. 4 is a structural diagram of cluster 1 after molecular completion of the molecular structure in Fig. 3;

Fig. 5 is a structural diagram of cluster 2 after the central molecule in Fig. 2 is used as the center of the sphere, and _R2 is used as the cut-off radius for atomic interception and completion;

Fig. 6 is a schematic structural diagram of a molecular crystal energy calculation device provided in an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Embodiments of the present invention

Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of this application to those skilled in the art.

The terminology used in this application is for the purpose of describing particular embodiments only, and is not intended to limit the application. As used in this application and the appended claims, the singular forms "a", "the", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the term "and/or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first", "second", "third" and so on may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of the present application, first information may also be called second information, and similarly, second information may also be called first information. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

In related technologies, when calculating the energy of a crystal, a large number of cluster structures are usually extracted from the crystal to perform two-body, three-body, or even four-body calculations. However, with the increase in precision requirements and the consideration of many-body effects, the size and number of clusters increase rapidly, which will result in complex calculation procedures and high costs. Moreover, at present, low-precision methods are often used to calculate crystal energy, which also introduces certain errors.

In view of the above problems, the embodiments of the present application provide a molecular crystal energy calculation method, device and storage medium. By establishing a "core-shell" calculation scheme, the calculation efficiency and calculation accuracy of crystal energy can be improved.

The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

The embodiment of the present application provides a molecular crystal energy calculation method. As shown in Figure 1, the method may include the following steps:

S110. Obtain the target crystal structure, and determine the central molecule, M clusters and M shell structures from the target crystal structure. Wherein, M may be an integer greater than or equal to 1.

Wherein, the target crystal structure may be a crystal structure composed of a single molecule, or a crystal structure composed of multiple molecules, which is not limited here.

In one embodiment, the specific implementation of determining the central molecule, M clusters and M shell structures from the target crystal structure may include: selecting a molecule from the target crystal structure as the central molecule; taking the geometric center of the central molecule as The center of the sphere, and use M different preset radii as cut-off radii to intercept atoms of the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M clusters; divide the central molecule from each cluster Delete the corresponding M shell structures.

Wherein, if the target crystal structure is a crystal structure composed of a single molecule, a molecule can be randomly selected from the target crystal structure as the central molecule, or a molecule can be selected from near the geometric center of the target crystal structure as the central molecule.

If the target crystal structure is a crystal structure composed of two molecules (such as molecule A and molecule B), the molecule A and molecule B that are closest to each other (the distance between the molecular geometric centers is the shortest) can be selected from the target crystal structure together as the central molecule.

Furthermore, when constructing clusters, molecules with all atoms located within the cut-off radius can be selected to construct clusters, and molecules with only some atoms within the cut-off radius are excluded;

Alternatively, if only some atoms of a molecule are located within the cutoff radius, the molecule can be completed, and the completed molecules and molecules with all atoms within the cutoff radius can be used to construct clusters together. That is to draw a sphere with the geometric center of the central molecule and the radius R, select all the atoms within the radius R, and ensure that the sphere contains at least all the atoms on the first neighbor molecules of the central molecule, according to the crystal arrangement, the atoms are filled as For a complete molecule, the set of molecules is called a "cluster", and the cluster without the central molecule is called a "shell".

S120. Calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively by using a quantum chemical method.

Specifically, the molecular structure of the central molecule can be used as input, and the molecular energy of the central molecule and the sub-item energies that constitute the molecular energy can be calculated by using quantum chemical methods; the structure of each cluster is used as input, and the same quantum chemical method can be used Calculate the cluster energy of each cluster and the sub-item energies that constitute the cluster energy; take each shell structure as input, and use the same quantum chemical method to calculate the shell energy of each shell structure and the various components that constitute the shell energy. Itemized energy.

In one embodiment, the quantum chemical method can include a tight binding (Density Functional based Tight Binding, DFTB) method based on density functional theory, and the calculation method of each energy mentioned above can adopt the following formula:

E _energy = E _{0 approx} + E _scc + E _rep + E _nuc + E _{disp_corr} ; (1-1)

Among them, the sub-item energy E _{0 is approximately} the orbital energy under the zero-order approximation, E _scc is the second/third-order electrostatic energy, E _rep is the short-range repulsion energy of the valence bond, _Enuc is the nuclear repulsion energy, and E _{disp_corr} is the long-range repulsion energy dispersion correction capability. Since _Enuc is an exact value by default, no additional correction is required, here _Enuc and E _rep can be combined, or _Enuc can be ignored directly, that is, formula (1-1) can be expressed as: E _energy = E _{0 approximation} + E _scc +E _rep +E _{disp_corr} .

In one embodiment, the quantum chemical method may include a density functional theory (Density Functional Theory, DFT) method, and the calculation method of each energy mentioned above may adopt the following formula:

E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ; (1-2)

Among them, the sub-item energy E ₀ is the orbital energy, E _j is the electron electrostatic energy, _Ex is the exchange energy, E _c is the correlation energy, _Enuc is the nuclear repulsion energy, and E _{disp_corr} is the long-range dispersion correction energy.

It can be understood that, in addition to the aforementioned DFTB and DFT methods, the quantum chemical method can also use other semi-empirical methods or empirical force field methods, etc., which are not limited here.

Here, DFTB is taken as an example for further description. Taking the molecular structure of the central molecule as input, the molecular energy of the central molecule and its sub-items are calculated by formula (1-1).

Take the geometric center of the central molecule as the center of the sphere, and use the preset radius _R1 as the cut-off radius to perform atomic interception on the target crystal structure, and form a cluster with atoms within the range of the preset radius _R1 to obtain cluster 1; Taking the structure of cluster 1 as input, the cluster energy and its sub-items of cluster 1 are also calculated by formula (1-1); the central molecule is deleted from cluster 1 to obtain the structure of shell 1, and the shell 1 structure as input, the shell energy and its sub-items of shell 1 structure are also calculated by formula (1-1).

Still take the geometric center of the central molecule as the center of the sphere, and use the preset radius R ₂ as the cut-off radius to carry out atom interception on the target crystal structure, and form a cluster with atoms within the range of the preset radius R ₂ , and obtain cluster 2 ; With the structure of cluster 2 as input, the cluster energy and its subitems of cluster 2 are also calculated by formula (1-1); the central molecule is deleted from cluster 2 to obtain the shell 2 structure, and The shell 2 structure is taken as input, and the shell energy and its sub-items of the shell 2 structure are also calculated by using the formula (1-1).

Still take the geometric center of the central molecule as the center of the sphere, and use the preset radius R ₃ as the cut-off radius to carry out atom interception on the target crystal structure, and form a cluster with atoms within the range of the preset radius R ₃ , and obtain cluster 3 ;With the structure of cluster 3 as input, the cluster energy of cluster 3 and its sub-item energies are also calculated by formula (1-1); the central molecule is deleted from cluster 3 to obtain the structure of shell 3, and the The shell 3 structure is used as input, and the shell energy and its sub-items of the shell 3 structure are also calculated by using the formula (1-1).

S130. Calculate and obtain the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy.

In the embodiment of the present application, the molecular energy of the central molecule, the cluster energy of each cluster and the shell energy of each shell structure can be used to determine the interaction energy between the central molecule and each shell structure, and then use the mutual The action energy is extrapolated to obtain the lattice energy of the target crystal structure.

In one embodiment, according to the partial energies of molecular energy, the partial energies of each cluster energy, and the partial energies of each shell energy, the relationship between the central molecule and each Each sub-item energy of the interaction energy between the shell structures; further, according to each sub-item energy of the interaction energy between the central molecule and each shell structure, the second preset formula can be used to calculate the target crystal structure The subitem energies of the lattice energy; and then according to the subitem energies of the lattice energy and the contribution coefficients of the subitem energies, the lattice energy of the target crystal structure is calculated by using the third preset formula.

In this embodiment, the expression form of the first preset formula is as follows:

E _{shell n interaction energy, i} = E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ; (1-3)

Wherein, n is the cluster number, and the value of n is 1-M. i is the number of each sub-item energy, taking the DFTB method as an example, when i is 1, the corresponding sub-item energy is _{approximately E 0} ; when i is 2, the corresponding sub-item energy is E _scc ; when i is 3, The corresponding sub-item energy is E _rep ; when i is 4, the corresponding sub-item energy is _Enuc ; when i is 5, the corresponding sub-item energy is E _{disp_corr} . E _{cluster n,i} is the i-th sub-item energy of the cluster energy of the nth cluster, E _{molecule, i} is the i-th sub-item energy of the molecular energy of the central molecule, E _{-shell n,i} is the n-th sub-item energy The i-th sub-item energy of the shell energy of a shell structure, E _{shell n interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the n-th shell structure.

For example, according to the formula (1-3), the expression form of the i-th sub-item energy of the interaction energy between the central molecule and the first shell structure (shell 1 structure) is: E _{shell 1 interaction energy, i} = E _{cluster 1,i} – E _{molecule, i} – E _{shell 1,i} . The expression of the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure (shell 2 structure) is: E _{shell 2 interaction energy, i} = E _{cluster 2, i} - E _{molecule, i} –E _shell2,i .

Considering that the interaction energy between the shell structure and the central molecule under different cut-off radii (R _n ) may be attenuated, and the attenuation conforms to the attenuation function related to R _n . In one embodiment, when M is greater than or equal to 3, the second preset formula can be expressed as follows:

E _{shell n interaction energy.i} = E _{lattice, i} +A*(R _n ) ^-B ; (1-4)

Among them, E _{lattice, i} is the i-th partial energy of the lattice energy of the target crystal structure, R _n is the interception radius used when constructing the n-th cluster, A and B are two different attenuation coefficients, and Both A and B are unknown.

Correspondingly, each component energy of the interaction energy between the central molecule and each shell structure can be calculated using the second preset formula to obtain multiple sets of E _{lattices, i} , A and B; and for multiple sets of E _{Lattice, i} , A and B are fitted to obtain the sub-items of the lattice energy of the target crystal structure.

The E _{-shell n interaction energy .i} is used for energy extrapolation to obtain the E- _lattice,i . For extrapolation, the E _{-shell n interaction energy.i} and _Rn in formula (1-4) are known, and the E _{lattice, i} , A and B are unknown, so the interaction between the three shell structures and the central molecule can be used The action energy is solved for the E _lattice,i , A and B, and finally the E _lattice,i is obtained. For the case of more than 3 shell structures (M is greater than 3), a set of E _{lattices, i} , A and B can be obtained correspondingly by using each 3 shell structures, so as to obtain multiple sets of E _{lattices, i} , A and B, Then fit and optimize multiple groups of E _lattice,i , A and B, and finally obtain E _lattice,i . Preferably, performing fitting optimization on multiple sets of E _{lattices, i} , A and B may be performing averaging on multiple sets of E _{lattices, i} , A and B respectively. As the number of clusters (or shell structures) increases, R _n increases accordingly, which leads to a rapid increase in the calculation amount. In order to reduce the calculation amount and improve the calculation efficiency, the embodiment of the present application preferably has M within 3, that is, no more than 3 clusters.

It can be understood that, in addition to formula (1-4), other attenuation functions can also be used for the attenuation function, such as the following two representation functions:

E _{shell n interaction energy, i} = E _{lattice, i} +A*exp(-B*R _n );

E _{shell n interaction energy, i} = E _{lattice, i} + A*exp[-B*sqrt(R _n )];

In the above two functions, A and B are two different attenuation coefficients, and both A and B are unknown. The calculation process of E- _lattice,i can be similar to the calculation process of formula (1-4), and will not be repeated here.

For formula (1-4), B can usually be regarded as a physically determined parameter, and its theoretical value can be set to 3.0. Therefore, only E _{lattice, i} and A are unknown in formula (1-4). In one embodiment, when M is 2, the second preset formula can be converted from formula (1-4) to the following formula (1-5):

E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ]; (1-5)

Among them, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, E _{shell 1 interaction energy, i} is the ith part of the interaction energy between the central molecule and the first shell structure Subitem energy, E _{shell 2 interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the second shell structure, R ₁ is the intercept radius used when constructing the first cluster, R ₂ is the intercept radius used when constructing the second cluster.

At this time, only two clusters can be used for extrapolation, and the E _lattice,i can be calculated, which can further improve the calculation efficiency while ensuring the calculation accuracy.

In one embodiment, only one cluster structure can be used to calculate the shell interaction energy. At this time, extrapolation cannot be performed, but sub-items can still be used for fitting to obtain the E _lattice,i . Specifically, when M is 1, n is also 1, and the second preset formula can be expressed as follows:

E _{lattice, i} = E _{shell 1 interaction energy, i} = E _{cluster 1, i} -E _{molecule, i} - E _{shell 1, i} ; (1-6)

Among them, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, E _{shell 1 interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the shell structure .

In one embodiment, the expression form of the third preset formula is as follows:

E _lattice = sum(k _i E _{lattice, i} ); (1-7)

Among them, E _lattice is the lattice energy of the target crystal structure, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, k _i is the contribution of the i-th sub-item energy of the lattice energy coefficient.

In this embodiment, the contribution coefficients of each component energy of the lattice energy can be set empirical values, or a certain amount of E _{-shell n interaction energy .i} calculated before the calculation of the crystal energy, and compared with experiments or high The precision lattice can be combined and the fit determined.

Although the sub-items of the extrapolated lattice energies are directly summed, physically they should be equal to the lattice energy, but in practical applications, it is found that: a) Although the overall energy may be consistent, different methods have different performances in terms of sub-items The trend appears to be different; b) The energy difference of the sub-items may lead to large errors in the calculation of the lattice energy. Therefore, the experimental lattice energy or high-precision lattice energy is used as a reference here, and each lattice energy sub-item of the lower-precision method is recalibrated to obtain a lattice energy closer to the reference.

The following is a specific implementation method for fitting and determining the contribution coefficient of each sub-item energy:

1) Obtain multiple reference crystal structures and the reference lattice energy of each reference crystal structure.

Wherein, N reference crystal structures and reference lattice energies E _ref,j of these reference crystal structures can be collected from previous experimental results, literature reports and/or structure databases, where j is 1-N. The reference crystal structure refers to the crystal structure or experimental crystal structure predicted by theoretical methods (such as DFT, DFTB, etc.), and the reference lattice energy is the crystal lattice energy predicted by high-precision theoretical methods (such as DFT) or Test measurements.

2) Calculating the sub-item energies of the lattice energy of each reference crystal structure respectively.

Using the same calculation method as the calculation method for obtaining the sub-items of the lattice energy of the target crystal structure, the sub-items of the lattice energy of each reference crystal structure are calculated. Taking DFTB as an example, each reference crystal structure is used as input, and the sub-item energy of the lattice energy of each reference crystal structure can be obtained through the aforementioned series of calculations: E _{lattice, 0 approximation} , E _{lattice, scc} , E _{lattice, rep} , E _{lattice, disp_corr} , _Enuc .

Further, each sub-entry energy E _lattice,i of the lattice energy of N reference crystal structures can be organized into a matrix, and the representation of the matrix (X) is as follows:

And, the reference lattice energy E _ref,j of each reference crystal structure can be expressed in vector form:

E=[E _ref,1 E _ref,2 ... E _ref,N ] ^T ;

3) Set the contribution coefficient k _i of each component energy of the lattice energy.

Contribution coefficient _ki is a parameter to be determined, which can be expressed in vector form:

K=[k _{0 approximate} k _scc k _rep k _{disp_corr} k _nuc ] ^T ;

Since _Enuc is an exact value and does not require recalibration, the above vector K can be modified as:

K=[k _{0 approximate} k _scc k _rep k _{disp_corr} 1] ^T ;

4) According to the sub-items of the lattice energy of each reference crystal structure and the set contribution coefficients, the sub-items of the predicted lattice energy of each reference crystal structure are obtained.

Ideally, E=XK; and practically, E*=XK. Wherein, E* contains the sub-items of the predicted lattice energies of each reference crystal structure.

5) Use the sub-item energies of the reference lattice energy and the sub-item energies of the predicted lattice energy of each reference crystal structure to fit the set contribution coefficient, and obtain the contribution of each sub-item energy after fitting coefficient.

By adjusting K, E* is close to E, and K is obtained when the error between E* and E (such as root mean square error RMSE, mean square error MSE, etc.) is the smallest. In practical applications, the number N of the reference crystal structure is usually much larger than the number i of the sub-item energy, therefore, it can be obtained by directly fitting K using an optimization algorithm (such as the least square method).

S140. Calculate and obtain the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

In the embodiment of the present application, after obtaining the molecular energy of the central molecule and the lattice energy of the target crystal structure, the energy sum of the two can be calculated to obtain the total crystal energy of the target crystal structure. The specific calculation formula is as follows:

E _{total energy} = E _molecule + E _lattice = E _molecule + sum (k _i E _{lattice, i} ); (1-8)

Among them, E _{total energy} is the total crystal energy of the target crystal structure, E _molecule is the molecular energy of the central molecule, and E _lattice is the lattice energy of the target crystal structure.

Here, an Aspirin crystal is taken as an example for illustration. The Aspirin crystal has P21/c symmetry, and one unit cell contains 4 equivalent molecules. In this example, the low-precision DFTB method is selected to extrapolate the 2-shell structure and predict the total energy of the crystal. According to literature reports, the Aspirin lattice energy calculated by the high-precision DFT method is -118kJ/mol.

1) Select one of the 4 equivalent molecules as the central molecule, calculate E _{molecule, 0 approximation} , E _{molecule, scc} , E _{molecule, rep} , E _{molecule, disp_corr} . Wherein, the molecular structure of the central molecule in the Aspirin crystal is shown in FIG. 2 .

2) Use R ₁ =4.0 angstroms as the cut-off radius, and use the geometric center of the central molecule as the center of the sphere to select atoms, as shown in FIG. 3 , which shows the structures of all atoms within the cut-off radius R ₁ . It can be seen from the figure that the peripheral molecules are not complete, so the molecular completion operation is required;

3) Complement the incomplete molecules to obtain the structure of cluster 1 and shell 1. Figure 4 shows the structure of cluster 1 after the molecules are filled. The structure of the ball and stick model is represented as the central molecule, and the rest of the line model is the shell 1 structure.

4) Using R ₂ =8.0 angstroms as the cut-off radius, repeat the above steps 2) and 3) to obtain the structure of cluster 2 and shell 2. Figure 5 shows the completed structure of cluster 2, and the structure representation of the ball-and-stick model is the central molecule, and the rest of the line model is the shell 2 structure.

5) Calculate the sub-item energy of the central molecule, cluster 1, cluster 2, shell 1 and shell 2 structures by the DFTB method under the 3OB parameter, and obtain E _molecule,i , E _{cluster 1,i} , E _{shell 1,i} , E- _{cluster 2,i} and E- _{shell 2,i} , as shown in Table 1:

Table 1 The sub-item energy calculated by DFTB method under 3OB parameters (unit: a.u.)

6) Using formula (1-3), calculate the E _{-shell 1 interaction energy,i} and the E _{-shell 2 interaction energy,i} . In addition, extrapolation is performed using formula (1-5) to obtain the sub-item energy of the lattice energy. The energy data of each sub-item are shown in Table 2.

Table 2 The sub-item energies extrapolated by DFTB method under 3OB parameters (unit: a.u.)

7) Select the K _{DFTB, shell 1/2} that has been pre-fitted for DFTB, and use formula (1-7) to obtain the E _lattice . Using the parameters determined for DFTB/3OB in Table 2, the E _lattice =-119.8kJ/mol is obtained, which is very close to the value reported in the literature.

8) Use the formula (1-8) to calculate the total energy of the crystal. According to the above lattice energy, the total crystal energy of Aspirin crystal in the current method can be obtained: -83023.0kJ/mol.

Still taking Aspirin crystal as an example for illustration, the Aspirin crystal has P21/c symmetry, and one unit cell contains 4 equivalent molecules. In this example, the combination of the PBE-D3BJ method with normal precision and the 6-31G* basis set in the density functional theory (DFT) method is selected to predict the crystal energy of the 1-shell structure.

1) Select one of the 4 equivalent molecules as the central molecule, and calculate _Emol,0 , _{Emol, j} , _{Emol, x} , _{Emol, c} , Emol _{, nuc} , Emol _{, disp_corr} . The molecular structure of the central molecule is shown in Figure 2.

2) Use R ₁ =4.0 angstroms as the cut-off radius, and use the geometric center of the central molecule as the center of the sphere to select atoms. As shown in FIG. 3 , the structure of the ball-and-stick model is represented as the central molecule. Atoms selected with a cut-off radius of 4.0 angstroms, it can be seen that the peripheral molecules are not complete and need to be completed.

3) Completing the missing molecules to obtain the cluster 1 and shell 1 structures, as shown in FIG. 4 . The structure of the cluster 1 after the molecules are completed, the structure of the ball-and-stick model is the central molecule, and the rest is the shell 1 structure.

4) Use the PBE-D3BJ method and def-SV(P) to calculate the sub-item energies of the central molecule, cluster 1 and shell 1 structures, and obtain E _molecule,i , E _{cluster 1,i} , E _{shell 1, i} , its calculation method can refer to the formula (1-2), and use the formula (1-3) to calculate the E _{-shell 1 interaction energy, i} . The sub-item energies are shown in Table 3: Table 3 shows the components and current parameters obtained under PBE-D3BJ and def-SV(P).

Table 3 The sub-item energy obtained under PBE-D3BJ and def-SV(P) (unit: a.u.)

5) Select K _{PBE-D3BJ/6-31G*, shell 1} , which is pre-fitted for the PBE-D3BJ method and def-SV(P), and use formula (1-7) to obtain E _lattice = -117.1kJ/mol, It is also very close to the results of high-precision calculations reported in the literature.

6) Use the formula (1-8) to calculate the total energy of the crystal. According to the above lattice energy, the total crystal energy of the Aspirin crystal in the current method can be obtained: -1700088.5kJ/mol.

In one embodiment, energy correction can be performed on the molecular energy of the central molecule first to obtain the corrected molecular energy; then, the total crystal energy of the target crystal structure can be calculated by using the corrected molecular energy and lattice energy.

For example, the molecular energy and lattice energy are both calculated by the DFTB method, and then the molecular energy of the central molecule can be recalculated using a higher-precision method (such as the MP2/aug-cc-pVQZ method) to replace the previous The molecular energy calculated by the low-precision method (DFTB) is used to obtain better and more reliable molecular energy, and then the total energy of the crystal with higher confidence is obtained to further improve the calculation accuracy.

It can be understood that other correction methods may also be used, such as correcting at least one partial energy of the molecular energy, so as to obtain more reliable molecular energy.

The method provided in the embodiment of the present application establishes a "core-shell" calculation scheme by calculating the energy of the central molecule (core) and cluster (shell), which can avoid a large number of multi-body groups such as two-body and three-body groups in the prior art The cluster calculation can obtain higher energy accuracy than the original low-precision calculation method directly, and the calculation efficiency is also greatly improved.

This application uses the technology of central molecule-peripheral clusters to evaluate crystal energy, which is compatible with mainstream quantum chemical calculation methods, can better balance calculation accuracy and cost, and can be used for fast calculation of crystal energy.

This application can directly use a large cluster for calculation, which reduces the number of calculations and avoids the steps of dividing, screening and calculating small clusters such as two bodies in the existing method.

All calculations in this application can be performed with the same calculation accuracy, and a relatively high-precision total energy of the crystal can be obtained by introducing multiple empirical parameters according to energy items of different physical origins.

In this application, methods with different precision can be selected for the central molecular and shell structures, and the molecular energy and lattice energy can be processed with different high precision to obtain a more reliable total energy of the crystal.

In principle, this application uses the calculation results of the two shells for extrapolation. In actual use, the cluster can be fitted directly with a low-precision method, and the lattice energy can be directly obtained to further improve the overall calculation efficiency.

The embodiment of the present application also provides a molecular crystal energy comparison method, including the following steps:

S210. Acquire at least two crystal structures to be compared.

S220. Calculate the crystal energy of each crystal structure by using the molecular crystal energy calculation method provided in the foregoing embodiments, and obtain the total crystal energy of each crystal structure.

S230. According to the total crystal energy of each crystal structure, determine the relationship between the crystal energies of the at least two crystal structures.

Using the above method, it is possible to quickly and accurately calculate the crystal energy of multiple crystal structures, and sort the energy of these crystal structures to determine the relationship between the crystal energy of each crystal structure, so that it can be quickly selected in subsequent applications. more stable crystal structure.

The embodiment of the present application also provides a molecular crystal energy calculation device, which can be used to implement the molecular crystal energy calculation method provided in the foregoing embodiments. As shown in Figure 6, the device may include:

An acquisition module 610, configured to acquire the target crystal structure, and determine the central molecule, M clusters and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

The first calculation module 620 is used to separately calculate the molecular energy of the central molecule, the cluster energy of each cluster and the shell energy of each shell structure by using a quantum chemical method;

The second calculation module 630 is used to calculate the lattice energy of the target crystal structure according to the molecular energy, cluster energy and shell energy;

The third calculation module 640 is used to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

Optionally, the implementation of determining the central molecule, M clusters and M shell structures from the target crystal structure by the acquisition module 610 may include: selecting a molecule from the target crystal structure as the central molecule; taking the geometric center of the central molecule as The center of the sphere, and use M different preset radii as cut-off radii to intercept atoms of the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M clusters; divide the central molecule from each cluster Delete the corresponding M shell structures.

Optionally, the obtaining module 610 may further include:

an acquisition unit, configured to acquire the target crystal structure;

Selection unit, used to select a molecule from the target crystal structure as the central molecule;

The interception unit is used to take the geometric center of the central molecule as the center of the sphere, and use M different preset radii as cut-off radii to carry out atomic interception on the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M a cluster;

The deletion unit is used to delete the central molecule from each cluster to obtain the corresponding M shell structures.

Optionally, the implementation of the acquisition module 610 selecting molecules with atoms within the cutoff radius to construct clusters may include: selecting molecules with all atoms within the cutoff radius to construct clusters; or, if there are molecules with only some atoms within the cutoff radius , complete the molecule and build clusters using the completed molecule and molecules with all atoms within the cutoff radius.

Optionally, the first calculation module 620 may further include:

The first calculation unit is used to use the molecular structure of the central molecule as an input, and calculate the molecular energy of the central molecule and the sub-energy of the molecular energy by using quantum chemical methods;

The second calculation unit is used to use the structure of each cluster as an input to calculate the cluster energy of each cluster and the energy of each subitem of the cluster energy by using a quantum chemical method;

The third calculation unit is used to use each shell structure as an input to calculate the shell energy of each shell structure and the component energies constituting the shell energy by quantum chemical method.

Optionally, the quantum chemical method may include a tight-binding DFTB method based on density functional theory, and its energy calculation formula may be: E _energy = E _{0 approximation} + E _scc + E _rep + E _nuc + E _{disp_corr} ;

Among them, the sub-item energies E _{0 approximation} , E _scc , E _rep , _Enuc , and E _{disp_corr} are: orbital energy under zero-order approximation, second/third-order electrostatic energy, short-range repulsion energy of valence bonds, and nuclear repulsion energy , the long-range dispersion correction energy.

Optionally, the quantum chemical method may include a density functional theory DFT method, and its energy calculation formula may be: E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ;

Among them, the sub-items of energy E ₀ , E _j , _Ex , E _c , _Enuc , and E _{disp_corr} are: orbital energy, electron electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, and long-range dispersion correction energy.

Optionally, the second computing module 630 may further include:

The fourth calculation unit is used to calculate and obtain the central molecule and each sub-energy according to the sub-item energy of the molecular energy, the sub-item energy of each cluster energy, and the sub-item energy of each shell energy by using the first preset formula. The sub-items of the interaction energy between shell structures;

The fifth calculation unit is used to calculate the sub-items of the lattice energy of the target crystal structure by using the second preset formula according to the sub-items of the interaction energy between the central molecule and each shell structure;

The sixth calculation unit is used to calculate the lattice energy of the target crystal structure by using the third preset formula according to the component energies of the lattice energy and the contribution coefficients of the component energies.

Optionally, the first preset formula can be: E _{-shell n interaction energy, i} =E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ;

Among them, n is the cluster number, the value of n is 1~M, i is the number of each sub-item energy, E _{cluster n, i} is the i-th sub-item energy of the cluster energy of the nth cluster, E _{molecule, i} is the i-th partial energy of the molecular energy of the central molecule, E _{-shell n, i} is the i-th partial energy of the shell energy of the n-th shell structure, E _{-shell n interaction energy, i} is the center The energy of the ith component of the interaction energy between the molecule and the nth shell structure.

Optionally, when M is greater than or equal to 3, the second preset formula may be:

E _{shell n interaction energy. i} = E _{lattice, i} +A*(R _n ) ^-B ;

Among them, E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, R _n is the intercept radius used when constructing the n-th cluster, and A and B are two different attenuation coefficients;

At this time, the fifth calculation unit can specifically be used to calculate the sub-item energies of the interaction energy between the central molecule and each shell structure using the second preset formula to obtain multiple sets of E _{lattices, i} , A and B: Fit multiple groups of E _{lattice, i} , A and B to obtain the sub-item energy of the lattice energy of the target crystal structure.

Optionally, when M is 2, the second preset formula can be:

E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ];

Among them, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, E _{shell 1 interaction energy, i} is the ith part of the interaction energy between the central molecule and the first shell structure Subitem energy, E _{shell 2 interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the second shell structure, R ₁ is the intercept radius used when constructing the first cluster, R ₂ is the intercept radius used when constructing the second cluster.

Optionally, when M is 1, n is 1, the second preset formula can be: E _{lattice, i} =E _{shell 1 interaction energy, i} ;

Among them, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, E _{shell 1 interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the shell structure .

Optionally, the third preset formula can be: E _-lattice =sum(k _i E _-lattice,i );

Among them, E _lattice is the lattice energy of the target crystal structure, E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, k _i is the contribution of the i-th sub-item energy of the lattice energy coefficient.

Optionally, the way for the sixth calculation unit to calculate the contribution coefficients of each sub-item energy of the lattice energy may include: obtaining multiple reference crystal structures and the reference lattice energy of each reference crystal structure; Each sub-item energy of the lattice energy; set the contribution coefficient of each sub-item energy of the lattice energy; according to each sub-item energy of the lattice energy of each reference crystal structure and the set contribution coefficient, get each reference Each sub-entry energy of the predicted lattice energy of the crystal structure; use each sub-item energy of the reference lattice energy of each reference crystal structure and each sub-item energy of the predicted lattice energy to fit the set contribution coefficient, The contribution coefficient of each sub-item energy after fitting is obtained.

Optionally, the third calculation module 640 may further include:

A correction unit is used to perform energy correction on molecular energy to obtain corrected molecular energy;

The seventh calculation unit is used to calculate the total crystal energy of the target crystal structure by using the corrected molecular energy and lattice energy.

The device in the embodiment of this application establishes a "core-shell" calculation scheme by calculating the energy of the central molecule (core) and cluster (shell), which can avoid a large number of multi-body groups such as two-body and three-body groups in the prior art The cluster calculation can obtain higher energy accuracy than the original low-precision calculation method directly, and the calculation efficiency is also greatly improved.

Regarding the apparatus in the above embodiments, the specific manner in which each module executes operations has been described in detail in the embodiments related to the method, and will not be described in detail here.

The embodiment of the present application also provides a molecular crystal energy comparison device, which can be used to implement the molecular crystal energy comparison method provided in the foregoing embodiments. Specifically, the device may include:

an acquisition module, configured to acquire at least two crystal structures to be compared;

Calculation module, for calculating the crystal energy of each crystal structure by using the molecular crystal energy calculation device provided in the foregoing embodiments, to obtain the total crystal energy of each crystal structure;

The determination module is configured to determine the relationship between the crystal energies of the above-mentioned at least two crystal structures according to the total crystal energy of each crystal structure.

The embodiment of the present application also provides an electronic device, which can be used to implement the molecular crystal energy calculation method and/or the molecular crystal energy comparison method provided in the foregoing embodiments. As shown in FIG. 7 , an electronic device 700 includes a memory 710 and a processor 720 .

The processor 720 can be a central processing unit (Central Processing Unit, CPU), and can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), on-site Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

The memory 710 may include various types of storage units such as system memory, read only memory (ROM), and persistent storage. Wherein, the ROM may store static data or instructions required by the processor 720 or other modules of the computer. The persistent storage device may be a readable and writable storage device. Persistent storage may be a non-volatile storage device that does not lose stored instructions and data even if the computer is powered off. In some embodiments, the permanent storage device adopts a mass storage device (such as a magnetic or optical disk, flash memory) as the permanent storage device. In some other implementations, the permanent storage device may be a removable storage device (such as a floppy disk, an optical drive). The system memory can be a readable and writable storage device or a volatile readable and writable storage device, such as dynamic random access memory. System memory can store some or all of the instructions and data that the processor needs at runtime. In addition, the memory 710 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and magnetic disks and/or optical disks may also be used. In some embodiments, memory 710 may include a readable and/or writable removable storage device, such as a compact disc (CD), a read-only digital versatile disc (e.g., DVD-ROM, dual-layer DVD-ROM), Read-only Blu-ray Disc, Super Density Disc, Flash memory card (such as SD card, min SD card, Micro-SD card, etc.), magnetic floppy disk, etc. Computer-readable storage media do not contain carrier waves and transient electronic signals transmitted by wireless or wire.

Executable codes are stored in the memory 710 , and when the executable codes are processed by the processor 720 , the processor 720 can be made to execute part or all of the methods mentioned above.

In addition, the method according to the present application can also be implemented as a computer program or computer program product, the computer program or computer program product including computer program code instructions for executing some or all of the steps in the above method of the present application.

Alternatively, the present application may also be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium), on which executable code (or computer program or computer instruction code) is stored, When the executable code (or computer program or computer instruction code) is executed by the processor of the electronic device (or server, etc.), the processor is made to perform part or all of the steps of the above-mentioned method according to the present application.

Having described various embodiments of the present application above, the foregoing description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and alterations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principle of each embodiment, practical application or improvement of technology in the market, or to enable other ordinary skilled in the art to understand each embodiment disclosed herein.

Claims (32)

1. A molecular crystal energy calculation method, characterized in that it comprises:

   Obtaining a target crystal structure, and determining a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

   Calculating the molecular energy of the central molecule, the cluster energy of each of the clusters, and the shell energy of each of the shell structures using quantum chemical methods;

   calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy;

   According to the molecular energy and the lattice energy, the total crystal energy of the target crystal structure is calculated.
2. The method according to claim 1, wherein said determining central molecule, M clusters and M shell structures from said target crystal structure comprises:

   selecting a molecule from the target crystal structure as the central molecule;

   Take the geometric center of the central molecule as the center of the sphere, and use M different preset radii as cut-off radii to carry out atomic interception on the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M said clusters;

   The central molecule is deleted from each of the clusters to obtain the corresponding M shell structures.
3. The method according to claim 2, wherein said selection of molecules whose atoms are located within said cutoff radius to construct clusters comprises:

   selecting molecules with all atoms within the cut-off radius to construct clusters; or,

   If only some atoms of a molecule are located within the cutoff radius, the molecules are completed, and the completed molecules and molecules with all atoms located within the cutoff radius are used to construct clusters.
4. The method according to claim 1, characterized in that, the molecular energy of the central molecule, the cluster energy of each of the clusters and the shell energy of each of the shell structures are calculated respectively by using a quantum chemical method, include:

   Using the molecular structure of the central molecule as an input, calculating the molecular energy of the central molecule and the sub-energies that constitute the molecular energy by using quantum chemical methods;

   Using the structure of each of the clusters as an input, the quantum chemical method is used to calculate the cluster energy of each of the clusters and the component energies that constitute the cluster energy;

   Each of the shell structures is used as an input, and the quantum chemical method is used to calculate the shell energy of each shell structure and the component energies constituting the shell energy.
5. The method according to claim 4, wherein said quantum chemical method comprises a tight-binding DFTB method based on density functional theory, and the energy calculation formula is:

   E _energy = E _{0 approx} + E _scc + E _rep + E _nuc + E _{disp_corr} ;

   Among them, the sub-item energies E _{0 approximation} , E _scc , E _rep , _Enuc , and E _{disp_corr} are: orbital energy under zero-order approximation, second/third-order electrostatic energy, short-range repulsion energy of valence bonds, and nuclear repulsion energy , the long-range dispersion correction energy.
6. The method according to claim 4, wherein the quantum chemical method comprises a density functional theory DFT method, and the energy calculation formula is:

   E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ;

   Among them, the sub-items of energy E ₀ , E _j , _Ex , E _c , _Enuc , and E _{disp_corr} are: orbital energy, electron electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, and long-range dispersion correction energy.
7. The method according to claim 4, wherein the calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy comprises:

   According to the partial energies of the molecular energy, the partial energies of each of the cluster energies, and the partial energies of each of the shell energies, the relationship between the central molecule and each - Partial energies of the interaction energy between said shell structures;

   According to the sub-items of the interaction energy between the central molecule and each of the shell structures, the sub-items of the lattice energy of the target crystal structure are calculated using a second preset formula;

   According to the component energies of the lattice energy and the contribution coefficients of the component energies, the lattice energy of the target crystal structure is calculated using a third preset formula.
8. The method according to claim 7, wherein the first preset formula is:

   E _{shell n interaction energy, i} = E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ;

   Wherein, the n is the cluster number, the value of n is 1-M, the i is the number of each sub-item energy, and the E _{cluster n,i} is the cluster energy of the nth cluster The i-th partial energy of the E _{molecule, i} is the i-th partial energy of the molecular energy of the central molecule, and the E _{shell n,i} is the i-th shell energy of the n-th shell structure Subitem energy, the E _{shell n interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the nth shell structure.
9. The method according to claim 8, wherein when the M is greater than or equal to 3, the second preset formula is:

   E _{shell n interaction energy. i} = E _{lattice, i} +A*(R _n ) ^-B ;

   Wherein, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, the R _n is the intercept radius adopted when constructing the n-th cluster, and the A and The B is two different attenuation coefficients;

   The sub-items of the interaction energy between the central molecule and each of the shell structures are calculated using a second preset formula to obtain the sub-items of the lattice energy of the target crystal structure, including :

   calculating the partial energies of the interaction energy between the central molecule and each of the shell structures using the second preset formula to obtain multiple sets of the E _lattice,i , A and B;

   Fitting multiple sets of _{lattice E,i} , A, and B to obtain subitem energies of lattice energies of the target crystal structure.
10. The method according to claim 8, wherein when the M is 2, the second preset formula is:

    E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ];

    Wherein, the E _{lattice, i} is the ith partial energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the distance between the central molecule and the first shell structure The i-th partial energy of the interaction energy, the E _{-shell 2 interaction energy, i} is the i-th partial energy of the interaction energy between the central molecule and the second shell structure, the R ₁ is the cut-off radius used when constructing the first cluster, and R ₂ is the cut-off radius used when constructing the second cluster.
11. The method according to claim 8, wherein when the M is 1, the n is 1, and the second preset formula is:

    E _{lattice, i} = E _{shell 1 interaction energy, i} ;

    Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the interaction between the central molecule and the shell structure energy of the i-th component of energy.
12. The method according to claim 7, wherein the third preset formula is:

    E _lattice = sum(k _i E _{lattice, i} );

    Wherein, the E _lattice is the lattice energy of the target crystal structure, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, and the _ki is the The contribution coefficient of the i-th component energy of the lattice energy.
13. The method according to claim 7, wherein the calculation method of the contribution coefficient of each sub-item energy of the lattice energy comprises:

    obtaining a plurality of reference crystal structures and reference lattice energies for each of said reference crystal structures;

    separately calculating the partial energies of the lattice energies of each said reference crystal structure;

    Setting the contribution coefficient of each component energy of the lattice energy;

    Obtaining the sub-items of the predicted lattice energy of each of the reference crystal structures according to the sub-items of the lattice energy of each of the reference crystal structures and the set contribution coefficient;

    Using the sub-items of the reference lattice energy and the sub-items of the predicted lattice energy of each of the reference crystal structures, fitting the set contribution coefficients to obtain the fitting contribution of each sub-item energy coefficient.
14. The method according to any one of claims 1-13, wherein the calculation of the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy comprises:

    performing energy correction on the molecular energy to obtain the corrected molecular energy;

    Using the corrected molecular energy and the lattice energy, the total crystal energy of the target crystal structure is calculated.
15. A molecular crystal energy comparison method, characterized in that, comprising:

    obtaining at least two crystal structures to be compared;

    Carry out crystal energy calculation for each described crystal structure by using the method as described in any one of claims 1-14, to obtain the total crystal energy of each described crystal structure;

    According to the total crystal energy of each of the crystal structures, the magnitude relationship of the crystal energies of the at least two crystal structures is determined.
16. A molecular crystal energy calculation device, characterized in that it includes:

    An acquisition module, configured to acquire a target crystal structure, and determine the central molecule, M clusters and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

    The first calculation module is used to separately calculate the molecular energy of the central molecule, the cluster energy of each of the clusters and the shell energy of each of the shell structures by using a quantum chemical method;

    A second calculation module, configured to calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy;

    The third calculation module is used to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.
17. The device according to claim 16, wherein the acquisition module determines the central molecule, M clusters and M shell structures from the target crystal structure, including:

    selecting a molecule from the target crystal structure as the central molecule;

    Take the geometric center of the central molecule as the center of the sphere, and use M different preset radii as cut-off radii to carry out atomic interception on the target crystal structure, select molecules whose atoms are within the cut-off radius to construct clusters, and obtain M said clusters;

    The central molecule is deleted from each of the clusters to obtain the corresponding M shell structures.
18. The device according to claim 17, wherein the acquisition module selects molecules whose atoms are located within the cut-off radius to construct clusters, including:

    selecting molecules with all atoms within the cut-off radius to construct clusters; or,

    If only some atoms of a molecule are located within the cutoff radius, the molecules are completed, and the completed molecules and molecules with all atoms located within the cutoff radius are used to construct clusters.
19. The device according to claim 16, wherein the first computing module comprises:

    The first calculation unit is used to use the molecular structure of the central molecule as an input, and calculate the molecular energy of the central molecule and the sub-energy of the molecular energy by using quantum chemical methods;

    The second calculation unit is used to use the structure of each cluster as an input to calculate the cluster energy of each cluster and the energy of each subitem of the cluster energy by using a quantum chemical method;

    The third calculation unit is used to use each shell structure as an input to calculate the shell energy of each shell structure and the component energies constituting the shell energy by quantum chemical method.
20. The device according to claim 19, wherein the quantum chemical method comprises a tight-binding DFTB method based on density functional theory, and the energy calculation formula is:

    E _energy = E _{0 approx} + E _scc + E _rep + E _nuc + E _{disp_corr} ;

    Among them, the sub-item energies E _{0 approximation} , E _scc , E _rep , _Enuc , and E _{disp_corr} are: orbital energy under zero-order approximation, second/third-order electrostatic energy, short-range repulsion energy of valence bonds, and nuclear repulsion energy , the long-range dispersion correction energy.
21. The device according to claim 19, wherein the quantum chemical method comprises a density functional theory (DFT) method, and the energy calculation formula is:

    E _energy = E ₀ +E _j +E _x +E _c +E _nuc +E _{disp_corr} ;

    Among them, the sub-items of energy E ₀ , E _j , _Ex , E _c , _Enuc , and E _{disp_corr} are: orbital energy, electron electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, and long-range dispersion correction energy.
22. The device according to claim 19, wherein the second computing module comprises:

    The fourth calculation unit is used to calculate using the first preset formula according to the sub-items of the molecular energy, the sub-items of each of the cluster energies, and the sub-items of each of the shell energies obtaining the partial energies of the interaction energy between the central molecule and each of the shell structures;

    The fifth calculation unit is used to calculate and obtain the lattice energy of the target crystal structure according to the component energies of the interaction energy between the central molecule and each of the shell structures by using the second preset formula. Itemized energy;

    The sixth calculation unit is configured to calculate the lattice energy of the target crystal structure by using a third preset formula according to the component energies of the lattice energy and the contribution coefficients of the component energies.
23. The device according to claim 22, wherein the first preset formula is:

    E _{shell n interaction energy, i} = E _{cluster n,i} -E _{molecule, i} -E _{shell n,i} ;

    Wherein, the n is the cluster number, the value of n is 1-M, the i is the number of each sub-item energy, and the E _{cluster n,i} is the cluster energy of the nth cluster The i-th partial energy of the E _{molecule, i} is the i-th partial energy of the molecular energy of the central molecule, and the E _{shell n,i} is the i-th shell energy of the n-th shell structure Subitem energy, the E _{shell n interaction energy, i} is the ith subitem energy of the interaction energy between the central molecule and the nth shell structure.
24. The device according to claim 23, wherein when the M is greater than or equal to 3, the second preset formula is:

    E _{shell n interaction energy. i} = E _{lattice, i} +A*(R _n ) ^-B ;

    Wherein, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, the R _n is the intercept radius adopted when constructing the n-th cluster, and the A and The B is two different attenuation coefficients;

    The fifth calculation unit is specifically used to calculate the component energies of the interaction energy between the central molecule and each of the shell structures using the second preset formula to obtain multiple sets of E _{crystals Lattice, i} , A and B; multiple sets of E _{lattice, i} , A and B are fitted to obtain the sub-item energy of the lattice energy of the target crystal structure.
25. The device according to claim 23, wherein when the M is 2, the second preset formula is:

    E- _{lattice, i} = [E _{shell 1 interaction energy, i} (R ₁ ) ³ -E _{shell 2 interaction energy, i} (R ₂ ) ³ ]/[(R ₁ ) ³ -(R ₂ ) ³ ];

    Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the distance between the central molecule and the first shell structure The i-th sub-item energy of the interaction energy, the E _{-shell 2 interaction energy, i} is the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, the R ₁ is the cut-off radius used when constructing the first cluster, and R ₂ is the cut-off radius used when constructing the second cluster.
26. The device according to claim 23, wherein when the M is 1, the n is 1, and the second preset formula is:

    E _{lattice, i} = E _{shell 1 interaction energy, i} ;

    Wherein, the E _{lattice, i} is the ith sub-item energy of the lattice energy of the target crystal structure, and the E _{shell 1 interaction energy, i} is the interaction between the central molecule and the shell structure energy of the i-th component of energy.
27. The device according to claim 22, wherein the third preset formula is:

    E _lattice = sum(k _i E _{lattice, i} );

    Wherein, the E _lattice is the lattice energy of the target crystal structure, the E _{lattice, i} is the i-th sub-item energy of the lattice energy of the target crystal structure, and the _ki is the The contribution coefficient of the i-th component energy of the lattice energy.
28. The device according to claim 22, characterized in that the sixth calculation unit calculates the contribution coefficient of each component energy of the lattice energy, including:

    obtaining a plurality of reference crystal structures and reference lattice energies for each of said reference crystal structures;

    separately calculating the partial energies of the lattice energies of each said reference crystal structure;

    Setting the contribution coefficient of each component energy of the lattice energy;

    Obtaining the sub-items of the predicted lattice energy of each of the reference crystal structures according to the sub-items of the lattice energy of each of the reference crystal structures and the set contribution coefficient;

    Using the sub-items of the reference lattice energy and the sub-items of the predicted lattice energy of each of the reference crystal structures, fitting the set contribution coefficients to obtain the fitting contribution of each sub-item energy coefficient.
29. The device according to any one of claims 16-28, wherein the third calculation module includes:

    a calibration unit, configured to perform energy calibration on the molecular energy to obtain the corrected molecular energy;

    A seventh calculation unit, configured to calculate the total crystal energy of the target crystal structure by using the corrected molecular energy and the lattice energy.
30. A molecular crystal energy comparison device, characterized in that it comprises:

    an acquisition module, configured to acquire at least two crystal structures to be compared;

    A calculation module, configured to calculate the crystal energy of each of the crystal structures by using the device according to any one of claims 16-29 to obtain the total crystal energy of each of the crystal structures;

    The determination module is configured to determine the relationship between the crystal energies of the at least two crystal structures according to the total crystal energy of each of the crystal structures.
31. An electronic device, characterized in that it comprises:

    processor; and

    A memory on which executable code is stored, and when the executable code is executed by the processor, causes the processor to execute the method according to any one of claims 1-15.
32. A computer-readable storage medium, on which executable code is stored, and when the executable code is executed by a processor of an electronic device, the processor is made to execute the method described in any one of claims 1-15. method.

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