Example: Transition state search Ethane¶
#!/bin/sh
AMS_JOBNAME=0D $AMSBIN/ams << EOF
Task TransitionStateSearch
GeometryOptimization
Convergence Energy=1.25e-6
End
Properties
NormalModes true
End
System
Atoms
C 0.000000000000 0.000000000000 0.767685465031
C 0.000000000000 0.000000000000 -0.767685465031
H 0.964354016767 0.347635559279 1.177128271450
H -0.181115782790 -1.008972856410 1.177128271450
H -0.783238233981 0.661337297125 1.177128271450
H -0.500471876676 0.894626767091 -1.177128271450
H -0.524533568868 -0.880734742626 -1.177128271450
H 1.025005445540 -0.013892024465 -1.177128271450
End
End
Engine DFTB
Model SCC-DFTB
ResourcesDir DFTB.org/mio-1-1
EndEngine
EOF
# For periodic systems the rotation around C-C bond does not have to be lowest mode.
# Rotations of the molecule as the whole will likely have a smaller force constant.
# Since we do not want to search for a TS in molecular rotation we have to specify
# a reaction coordinate as precisely as possible..
AMS_JOBNAME=1D $AMSBIN/ams << EOF
Task TransitionStateSearch
TransitionStateSearch
ReactionCoordinate
Dihedral 3 1 2 6 0.3
Dihedral 3 1 2 8 0.3
Dihedral 3 1 2 7 0.3
Dihedral 5 1 2 6 0.3
Dihedral 5 1 2 8 0.3
Dihedral 5 1 2 7 0.3
Dihedral 4 1 2 6 0.3
Dihedral 4 1 2 8 0.3
Dihedral 4 1 2 7 0.3
End
End
GeometryOptimization
Convergence Energy=1.25e-6 Gradients=1.e-5
End
Properties
NormalModes true
End
System
Atoms
C 0.000000000000 0.000000000000 0.767685465031
C 0.000000000000 0.000000000000 -0.767685465031
H 0.964354016767 0.347635559279 1.177128271450
H -0.181115782790 -1.008972856410 1.177128271450
H -0.783238233981 0.661337297125 1.177128271450
H -0.500471876676 0.894626767091 -1.177128271450
H -0.524533568868 -0.880734742626 -1.177128271450
H 1.025005445540 -0.013892024465 -1.177128271450
End
Lattice
50.0 0.0 0.0
End
End
Engine DFTB
Model SCC-DFTB
ResourcesDir DFTB.org/mio-1-1
EndEngine
EOF
AMS_JOBNAME=2D $AMSBIN/ams << EOF
Task TransitionStateSearch
TransitionStateSearch
ReactionCoordinate
Dihedral 3 1 2 6 0.3
Dihedral 3 1 2 8 0.3
Dihedral 3 1 2 7 0.3
Dihedral 5 1 2 6 0.3
Dihedral 5 1 2 8 0.3
Dihedral 5 1 2 7 0.3
Dihedral 4 1 2 6 0.3
Dihedral 4 1 2 8 0.3
Dihedral 4 1 2 7 0.3
End
End
GeometryOptimization
Convergence Energy=1.25e-6 Gradients=1.e-5
End
Properties
NormalModes true
End
System
Atoms
C 0.000000000000 0.000000000000 0.767685465031
C 0.000000000000 0.000000000000 -0.767685465031
H 0.964354016767 0.347635559279 1.177128271450
H -0.181115782790 -1.008972856410 1.177128271450
H -0.783238233981 0.661337297125 1.177128271450
H -0.500471876676 0.894626767091 -1.177128271450
H -0.524533568868 -0.880734742626 -1.177128271450
H 1.025005445540 -0.013892024465 -1.177128271450
End
Lattice
50.0 0.0 0.0
0.0 50.0 0.0
End
End
Engine DFTB
Model SCC-DFTB
ResourcesDir DFTB.org/mio-1-1
EndEngine
EOF
AMS_JOBNAME=3D $AMSBIN/ams << EOF
Task TransitionStateSearch
TransitionStateSearch
ReactionCoordinate
Dihedral 3 1 2 6 0.3
Dihedral 3 1 2 8 0.3
Dihedral 3 1 2 7 0.3
Dihedral 5 1 2 6 0.3
Dihedral 5 1 2 8 0.3
Dihedral 5 1 2 7 0.3
Dihedral 4 1 2 6 0.3
Dihedral 4 1 2 8 0.3
Dihedral 4 1 2 7 0.3
End
End
GeometryOptimization
Convergence Energy=1.25e-6 Gradients=1.e-5
End
Properties
NormalModes true
End
System
Atoms
C 0.000000000000 0.000000000000 0.767685465031
C 0.000000000000 0.000000000000 -0.767685465031
H 0.964354016767 0.347635559279 1.177128271450
H -0.181115782790 -1.008972856410 1.177128271450
H -0.783238233981 0.661337297125 1.177128271450
H -0.500471876676 0.894626767091 -1.177128271450
H -0.524533568868 -0.880734742626 -1.177128271450
H 1.025005445540 -0.013892024465 -1.177128271450
End
Lattice
50.0 0.0 0.0
0.0 50.0 0.0
0.0 0.0 50.0
End
End
Engine DFTB
Model SCC-DFTB
ResourcesDir DFTB.org/mio-1-1
EndEngine
EOF