#! /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.