Example: Raman: NH3¶

Download Freq_NH3_RAMAN.run

#! /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