Example: Analytic Frequencies: CN

Download CN_SecDeriv.run

#! /bin/sh


# Calculation of analytical second derivatives is requested by specifying:
#   AnalyticalFreq
#   End
# in the ADF input.

# A good quality is specified for the numerical Becke integration to be sure of
# reliable results. In general, it seems advisable to use high accuracy for
# heavy nuclei at the moment, whereas default integration accuracy is usually
# sufficient for light atoms. The precision of the fit may be improved with the
# ZlmFit block keyword.


$ADFBIN/adf <<eor
  title CN
  atoms
   N  -1.3  0.0   0.0
   C   0.0  0.0   0.0 
  end
  Basis 
   Type DZ
   Core None
  End
  charge -1 
  XC
   LDA Xonly
  End
  BeckeGrid
   quality good
  End
  AnalyticalFreq
End
eor

mv TAPE21 CN.t21
rm -f logfile

# After SCF is completed, the energy second derivatives matrix is calculated and
# analysed, which yields in this case one frequency.