An example input file for Claisen rearrangement is shown here:
# SC-AFIR/B3LYP/6-31G
0 1
C -1.322433333627 -0.191004529768 -5.056458847453
O -0.117589121079 -0.141054922890 -4.360876068708
C 1.037511100415 0.386370458061 -5.094749726597
C 2.095538783078 0.741337962377 -4.096793059742
C 3.363699604363 0.325233466850 -4.170820165619
C -2.347230811790 -0.936116727294 -4.637689212067
H -1.373298426629 0.442955137118 -5.941814932290
H -3.291614061978 -0.918537126486 -5.167838594679
H -2.266000652832 -1.561323096908 -3.756190003276
H 1.398414827714 -0.363343316808 -5.810546144389
H 0.716167628877 1.276136433020 -5.660180537770
H 1.767809953778 1.390718437759 -3.287502070113
H 3.705333893087 -0.336339184132 -4.963481814281
H 4.109271051637 0.628670401161 -3.442851675006
Options
Add Interaction
GAMMA = 200
END
NoBondRearrange
GauMem = 200
GauProc = 1
The first line specifies a job type (SC-AFIR), and an ab initio method (B3LYP/6-31G) following a number sign (#). You must leave the second line a blank line. The third line specifies charge and spin multiplicity (2S+1). The geometry is specified in lines 4-17; you have to use Cartesian coordinates and the Z-matrix is not supported. You can set options in the following lines.
The general format of input files (XXX.com) is:
# [Job type]/[Ab initio method]
(A blank line)
[Charge] [Spin multiplicity]
[Chemical symbol of atom 1] [Cartesian coordinates of atom 1]
[Chemical symbol of atom 2] [Cartesian coordinates of atom 2]
[Chemical symbol of atom 3] [Cartesian coordinates of atom 3]
[Chemical symbol of atom 4] [Cartesian coordinates of atom 4]
┆
Options
[Option 1]
[Option 2]
[Option 3]
[Option 4]
[Option 5]
┆
Note: The first character of the chemical symbol should be capitalized, but the second one should not.
Note: DO NOT put blank lines between the coordinate section and the Options keyword.
Note: DO NOT put blank lines between the Options keyword and the first option.
Note: DO NOT put blank lines between n-th option and (n+1)-th option.