Example: Excitation energies and polarizability: Au2¶

#! /bin/sh


# A calculation of response properties of the Au2 dimer, with ZORA relativistic
# corrections

# In the response module infinite symmetries cannot be handled (see the User's
# Guide), so we specify a lower subgroup in the input file, here D(8h).

# In this sample run the LB94 potential is used. The implementation implies that
# the XC potential is evaluated from the exact charge density, rather than the
# cheaper and faster fitted density (as is the case for other XC functionals).
# This means that the computation times are longer. In a small molecule like Au2
# this hardly shows, but in larger molecules the differences may be more
# significant. Note that the LB94 is a model potential, thus the calculated bond
# energy has not so much meaning. If the BASIS key is specified and the model
# potential LB94 is used, in the create run of the atoms the BP86 functional is used.

# Excitation energies are computed, in principle the lowest 10 in each irrep of
# the symmetry (see the User's Guide for more details).

$AMSBIN/ams <<eor
System
  atoms
     Au   0.0 0.0 1.236
     Au   0.0 0.0 -1.236
  end
end

Task SinglePoint

Engine ADF
  title Au2, Response Properties
  excitations
    lowest 10
    tolerance 1e-10
  end
  basis
    PerAtomType Symbol=Au File=ZORA/DZ/Au.4d
  end
  response
    allcomponents
  end
  symmetry D(8h)
  xc
    gga LB94
  end
EndEngine

eor