JPH07230480A - Generating and plotting system for electron density face/ molecular orbital face - Google Patents

Abstract

PURPOSE:To provide the electron density face/molecular orbital face generating and plotting system which is much more efficient than conventional without degrading the plotting precision by setting a plotting area so that a plotting object is effectively included. CONSTITUTION:Data required for calculation or the electron density/molecular orbital like polar coordinate values of respective atoms constituting a molecule is read in from a data input part (1). Next, prescribed values or the plotting area are set. The plotting area considered to include an equivalent race or the ejection density/molecule orbital of the plotting object based on read-in data is set again in a molecular structure based on user's experience for the purpose or setting the plotting area again (2). Several representative points on the plotting area set again are selected by an electron density value/molecular orbital value calculation part (3), and electron density values/ molecular orbital values on these points are calculated to evaluate the plotting area. If there is a problem, the plotting area is set again. If there is no problems, the plotting area is divided into lattices, and electron density values/molecular orbital values on all lattice points are calculated and are converted to geometrical information and are plotted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron density plane / molecular orbital plane generation / drawing method, and more particularly to a method capable of generating and drawing an electron density plane / molecular orbital plane to be drawn with high drawing accuracy.

[0002]

2. Description of the Related Art Conventional generation of electron density plane / molecular orbital plane
The drawing method will be described.

First, data such as types of atoms in the molecule, coordinates, atomic basis functions, etc. necessary for calculating the electron density / molecular orbital is read.

Next, a drawing area is set in order to calculate the electron density / molecular orbital. As a setting method, a first method of setting a drawing area so that the whole molecule can be calculated from the read data, and a second method of manually inputting the drawing area when the drawing area is determined in advance And are being done.

Then, the set drawing area is divided into three-dimensional lattices, and the electron density value / molecular orbital function value on each lattice point is calculated. The number of grid divisions is usually constant regardless of the size of the drawing area.

Next, from the calculated electron density value / molecular orbital function value, information of the isosurface to be drawn is generated, converted into geometric information and drawn.

If necessary, enlargement / reduction operation is performed on the drawn electron density plane / molecular orbital plane to adjust the display range so that it is easy to see.

Regarding the display of molecules and the like, the display target is different, but as an example of the first method for setting the drawing area, there is Japanese Patent Laid-Open No. 3-246772, and as an example of the second method, Japanese Patent Application Laid-Open No. Sho. 64-84387 and the like.

[0009]

In the above-mentioned conventional electron density plane / molecular orbital plane generation / drawing method, the drawing area is set according to the object to be drawn (electron density plane / molecular orbital plane). Since it is set regardless of whether it is effectively included in the drawing area, there are the following two problems.

First, when the set drawing area is large, the object to be drawn becomes local in the drawing area and the drawing accuracy becomes coarse, and the area portion not necessary for drawing is not calculated. There is a problem that it should not be.

Secondly, there is a problem that the drawing target may not be included in the set drawing area.

An object of the present invention is to set a drawing area so as to effectively include a drawing object, so that the drawing accuracy is not lowered and the electron density surface / area is much more efficient than the conventional one.
It is to provide a method for generating and drawing a molecular orbital plane.

[0013]

An electron density plane / molecular orbital plane generation / drawing method of the first invention is a data input means for reading data required for calculation of electron density / molecular orbital, and an electron to be drawn. Drawing area setting / optimizing means for setting a drawing area including the density plane / molecular orbital plane and optimizing it
Electron density value / molecular orbital function value calculation means for calculating the electron density value / molecular orbital function value in the drawing area, and an equivalent value of electron density / molecular orbital from the calculated electron density value / molecular orbital function value And isosurface drawing means for drawing a surface.

The electron density plane / molecular orbital plane generation / drawing method of the second invention is the same as the electron density plane / molecular orbital plane generation / drawing method of the first invention. A plurality of points in the drawn region are selected, and the calculation of the electron density value / molecular orbital function value at that point is instructed to the electron density value / molecular orbital function value calculation means, and the electron density surface / molecular orbital of the drawing target is calculated by this calculated value. It is characterized in that it is determined that a surface is included in the set drawing area with appropriate accuracy, and if not, a new drawing area is set and the above judgment is repeated to optimize the drawing area. There is.

[0015]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the generation / drawing method of the electron density plane / molecular orbital plane of the present invention.

The electron density plane / molecular orbital plane generation / drawing method of this embodiment is, as shown in FIG. 1, a data input unit 1 for reading data for calculating electron density / molecular orbitals.
And a drawing area setting / optimizing unit 2 for determining an area in which the electron density plane / molecular orbital plane of the drawing object can be drawn with appropriate accuracy before calculating the electron density / molecular orbital, and the electron density in the drawing area / An electron density value / molecular orbital function value calculation unit 3 for calculating a molecular orbital, and an isosurface drawing unit 4 for drawing an isodensity / molecular orbital isosurface from the calculated electron density value / molecular orbital function value It is configured to include and.

FIG. 2 is a flow chart showing the operation of this embodiment. In addition, in correspondence with the configuration diagram of FIG. 1, step 101 is the data input section 1, steps 102 to 107 are the drawing area setting / optimizing section 2, steps 106 and 108 are the electron density value / molecular orbital function value calculating section 3, Step 109 is the isosurface drawing unit 4.

First, the data necessary for calculating the electron density / molecular orbital is read from the data input section 1 (step 101). The data to be read in here includes nuclear coordinate values of each atom constituting the molecule and values defining a basis function describing the orbit of the electron in the atom.

Next, first, the default value of the drawing area is set (step 102). The setting of the default value of the drawing area is to set the drawing area so as to include the entire molecule from the data read in step 101, and to set the predetermined area value if there is any.

If the default drawing area is acceptable, the process proceeds to step 106.

When the electron density / molecular orbital isosurface of the drawing target is local, and when a drawing region including the entire molecule is adopted, as described above, the drawing precision becomes rough and unnecessary calculation is performed. Therefore, it is desirable to reset and localize the drawing area according to the isodensity surface of the electron density / molecular orbital of the drawing object.

In order to reset this drawing area (YES branch of step 103), in the present embodiment, next step 1
Based on the data read in 01, a molecular structure (hereinafter referred to as molecular skeleton) in which atoms and bonds between atoms are displayed in a three-dimensional space is displayed (step 103), and the electron density of the drawing target / the iso-surface of the molecular orbit The drawing area that is considered to include is reset to this molecular skeleton based on the experience of the user (step 105).

The drawing area is set as follows.

The first is to specify the center and radius of a sphere on a displayed molecular skeleton with a pointing device such as a mouse, or to specify the center coordinate of the sphere and the length of the radius.
Enter a numerical value from the keyboard and use the rectangular parallelepiped with which the sphere is inscribed as the drawing area. Each surface of the rectangular parallelepiped is set to be perpendicular to the three-dimensional coordinate axis. Initial values are set in the drawing area, and the range is displayed in a spherical shape together with the molecular skeleton. The initial values are the center of the sphere = the center of the molecule, the radius of the sphere = the distance from the center to the furthest nucleus. If you want to change only the radius, stretch or shrink the surface of the sphere in the drawing area with the mouse.

Secondly, on the displayed molecular skeleton, the eccentric point of the rectangular parallelepiped (two vertices that are not on the same plane of the rectangular parallelepiped) to be a drawing area is designated by a pointing device such as a mouse, or Enter the eccentricity coordinates numerically. Also in this case, each surface of the rectangular parallelepiped is set to be perpendicular to the three-dimensional coordinate axis. An initial value is set for the drawing range, and the range is displayed as a rectangular parallelepiped together with the molecular skeleton. The initial value is the default drawing range. If you want to change only the size of the drawing range, move one of the eccentric points in that range with the mouse to change it.

Next, several representative points on the reset drawing area are selected, and the electron density value / molecular orbital function value on that point is calculated (step 106). This is because the drawing area reset from the molecular skeleton is evaluated from the electron density value / molecular orbital function value actually drawn.

That is, how the electron density plane / molecular orbital plane to be drawn is drawn in the reset drawing area is determined from the electron density value / molecular orbital function value at the representative point. When selecting the representative points, set all the grid points on the surface of the rectangular parallelepiped set as the drawing area as the representative points, and set the center points of the vertices and faces set as the drawing areas as the representative points. There is a case where the central point of the surface of the rectangular parallelepiped is used as the representative point.

Ideally, the electron density value / molecular orbital function value for all the grid points in the drawing area should be evaluated. For example, consider a grid in which the drawing area is divided into 10 equal parts in each XYZ axis direction. Looking at it, 10 * 10 * 10 = 100
The electron density value / molecular orbital function value must be calculated for 0 lattice points, and it takes too much time and is not practical in the course of trial and error of determining the drawing area.

Thus calculated electron density value /
The drawing area set from the molecular orbital function value is evaluated (step 107). That is, it is determined whether the set drawing area is appropriate for the electron density plane / molecular orbital plane to be drawn. Specifically, the calculated electron density value / molecular orbital function value of the representative point is compared with the electron density surface / molecular orbital surface electron density value / molecular orbital function value of the drawing target to set the drawing area. It is investigated whether or not the electron density plane / molecular orbital plane can be drawn appropriately (the most accurate drawing can be done in the drawing area with the smallest drawing target).

If there is a problem in the drawing area (step 107)
No branch), the process returns to step 104 and the drawing area is set again.

Next, if the evaluation of the drawing area in step 107 is good (YES branch in step 107), the set drawing area is divided into grids as calculation areas, and electron density values / molecular orbitals on all grid points are calculated. Calculate the function value (step 1
08).

Information of the isosurface to be drawn is generated from the calculated electron density value / molecular orbital function value, which is converted into geometric information and drawn (step 109).

When it is desired to change the drawing range again from the electron density plane / molecular orbital plane drawn in step 109 (YES branch of step 110), the process returns to step 104 to reset the drawing area again.

As described above, in the present embodiment, by setting the drawing area that effectively includes the drawing target, unnecessary calculation can be deleted without lowering the drawing accuracy, and the efficiency is remarkably higher than in the prior art. This has the effect that the electron density plane / molecular orbital plane can be generated and drawn.

[0036]

As described above, the electron density plane / molecular orbital plane generation / drawing method of the present invention does not reduce the drawing accuracy by setting the drawing area that effectively includes the drawing target. There is an effect that unnecessary calculation can be deleted, and the generation and drawing of the electron density plane / molecular orbital plane can be performed much more efficiently than in the past.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an electron density plane / molecular orbital plane generation / drawing method of the present invention.

FIG. 2 is a flow chart showing an example of the operation in the electron density plane / molecular orbital plane generation / drawing method of the present embodiment.

[Explanation of symbols]

 1 Data Input Section 2 Drawing Range Setting / Optimization Section 3 Electron Density Value / Molecular Orbital Function Value Calculation Section 4 Iso Surface Drawing Section 101-113 Steps of Flow Chart

Claims (2)

[Claims] 1. A data input means for reading data required for calculation of electron density / molecular orbital, and a drawing area setting for optimizing a drawing area including an electron density plane / molecular orbital plane of a drawing target. Optimizer and electron density value in the drawing area / electron density value for calculating molecular orbital function value /
An electron density surface comprising: a molecular orbital function value calculating means; and an isosurface drawing means for drawing an isodensity / molecular orbital isosurface from the calculated electron density value / molecular orbital function value. / Generation or drawing method of molecular orbital plane. 2. The drawing area setting / optimizing means selects a plurality of points in the set drawing area and sets the electron density value /
The calculation of the molecular orbital function value is instructed to the electron density value / molecular orbital function value calculation means, and the calculated value indicates that the electron density plane / molecular orbital plane to be drawn is included in the set drawing area with appropriate accuracy. The generation / drawing of the electron density plane / molecular orbital plane according to claim 1, characterized in that a new drawing area is set and a new drawing area is set if it is not, and the drawing area is optimized. method.