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Appendix A. Keyword Reference |  |
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Appendix A. Keyword Reference | |
GRID — Specify dimensions for a 2D reaction grid calculation.
GRID=nGRID(n,m)
A reaction grid calculation provides rough location of nearby stationary points by computing a 2D spirally-generated grid of points about the defined geometry. (The spiral-generation improves the opportunity for a smooth extrapolation for the initial guess for each successive point from the results from previous points.) The input structure always represents the center point of the generated grid. The GRID keyword is used to specify the size of the grid.
n
GRID=n specifies that an “n” by “n”-sized square grid will
be used. The value of “n” is 11 by default and may not exceed 19. An even value of n is
automatically shifted to the next larger odd value.
n,m)
A rectangular grid may be specified by passing two values to the GRID keyword.
GRID(n,m) specifies that an “n” by
“m”-sized rectangular grid will be used. The values of “n” and “m” are 11 by default and may
not exceed 19. An even value of n or m is automatically shifted to the next larger odd
value.
am1 rhf singlet qcscf t=auto step1=0.15 step2=0.15 grad minvis1,5-HEXADIENE INVERSION Rxn grid calculation C 0.000000 0 0.000000 0 0.000000 0 0 0 0 C 1.300000 1 0.000000 0 0.000000 0 1 0 0 C 1.540000 1 130.000000 1 0.000000 0 2 1 0 C 1.540000 -1 120.000000 1 0.000000 1 3 2 1
C 1.540000 1 120.000000 1 0.000000 1 4 3 2 C 2.190000 -1 110.000000 1 0.000000 1 1 2 3
H 1.000000 1 120.000000 1 90.000000 1 1 2 3 H 1.000000 1 120.000000 1 180.000000 1 1 2 7 H 1.000000 1 120.000000 1 -180.000000 1 2 3 4 H 1.000000 1 109.500000 1 120.000000 1 3 4 5 H 1.000000 1 109.500000 1 -120.000000 1 3 4 5 H 1.000000 1 109.500000 1 120.000000 1 4 3 2 H 1.000000 1 109.500000 1 -120.000000 1 4 3 2 H 1.000000 1 120.000000 1 120.000000 1 5 4 3 H 1.000000 1 120.000000 1 90.000000 1 6 5 4 H 1.000000 1 120.000000 1 180.000000 1 6 5 15 0 0.000000 0 0.000000 0 0.000000 0 0 0 0
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A reaction grid calculation will be performed if exactly two of optimization flags
are marked with a “-1”. The keywords
STEP1 and
STEP2 are also
required for a reaction grid. By default, an 11 x 11 grid is used unless
GRID= |
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This is the first reaction coordinate and will be incremented and decremented by the value of STEP1. |
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This is the second reaction coordinate and will be incremented and decremented by the value of STEP2. These two items will be used to construct a grid of points and optimizations will be carried out at each point on the surface. The point given in the geometry definition is the center of the grid and five steps are taken in each direction from this center point. The following list shows the values that the first and second reaction coordinates will take on. The center point is indicated by ×:
Step 1
0.79 0.94 1.09 1.24 1.39 1.54 1.69 1.84 1.99 2.14 2.29
1.44 o o o o o o o o o o o
1.59 o o o o o o o o o o o
1.74 o o o o o o o o o o o
S 1.89 o o o o o o o o o o o
t 2.04 o o o o o o o o o o o
e 2.19 o o o o o × o o o o o
p 2.34 o o o o o o o o o o o
2.49 o o o o o o o o o o o
2 2.64 o o o o o o o o o o o
2.79 o o o o o o o o o o o
2.94 o o o o o o o o o o o
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Copyright © 1992-2013 Semichem, Inc. All rights reserved. |
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