# Example: Raman: NH3¶

```
#! /bin/sh
# Summary:
# - Analytical frequencies with subsequent calculation of Raman intensities in a
# range
# - Numerical frequencies including all Raman intensities
# == Raman Intensities for Selected Frequencies ==
# The VibrationalAnalysis task (type ModeScanning) can be used to calculate Raman
# intensities for a range of frequencies only.
# The Raman intensities are calculated by numerical differentiation of the
# polarizability tensor. Only frequencies frequencies withing the interval
# that are known to be Raman-active will be included.
AMS_JOBNAME=NH3 $AMSBIN/ams <<eor
System
symmetrize
atoms
N 0.0000 0.0000 0.0000
H 0.4729 0.8190 0.3821
H -0.9457 0.0000 0.3821
H 0.4729 -0.8190 0.3821
end
end
Task SinglePoint
Properties
NormalModes True
End
thermo
temperatures 300:400:10
end
Engine ADF
title NH3 frequencies
beckegrid
quality good
end
basis
core Small
type TZP
end
EndEngine
eor
AMS_JOBNAME=RamanRange1 $AMSBIN/ams <<eor
LoadSystem
File NH3.results/ams.rkf
End
Task VibrationalAnalysis
VibrationalAnalysis
Type ModeScanning
NormalModes
ModeFile NH3.results/adf.rkf
ModeSelect
FreqRange 0.0 2000.0
End
End
End
Properties
Raman True
End
thermo
temperatures 300:400:10
end
EngineRestart NH3.results/adf.rkf
Engine ADF
title NH3 Raman intensities in the range 0-2000 cm-1
beckegrid
quality good
end
basis
core Small
type TZP
end
responseformalism response
EndEngine
eor
AMS_JOBNAME=RamanRange2 $AMSBIN/ams <<eor
LoadSystem
File NH3.results/ams.rkf
End
Task VibrationalAnalysis
VibrationalAnalysis
Type ModeScanning
NormalModes
ModeFile NH3.results/adf.rkf
ModeSelect
FreqRange 2000.0 5000.0
End
End
End
Properties
Raman True
End
EngineRestart NH3.results/adf.rkf
Engine ADF
title NH3 Raman intensities in the range 2000-5000 cm-1
beckegrid
quality good
end
basis
core Small
type TZP
end
responseformalism response
EndEngine
eor
# == Raman Intensities for All Frequencies ==
# Raman scattering intensities and depolarization ratios for all molecular
# vibrations at a certain laser frequency can be calculated in a single run.
# In this example the static Raman scattering is calculated (omega = 0). This
# type of calculation is very similar to an IR intensity calculation. In fact,
# all IR output is automatically generated as well. At all distorted geometries
# the dipole polarizability tensor is calculated. This is very time-consuming
# and is only feasible for small molecules.
AMS_JOBNAME=Raman $AMSBIN/ams <<eor
System
symmetrize
atoms
N 0.0000 0.0000 0.0000
H 0.4729 0.8190 0.3821
H -0.9457 0.0000 0.3821
H 0.4729 -0.8190 0.3821
end
end
Task SinglePoint
Properties
NormalModes True
Raman True
End
thermo
temperatures 300:400:10
end
Engine ADF
title NH3 frequencies with Raman intensities
beckegrid
quality good
end
basis
core Small
type TZP
end
response
raman
end
EndEngine
eor
```