#! /bin/sh


# Calculation of the (core) excitation energies of Ne including spin-orbit
# coupling.

# The state selective method (key SELECTEXCITATION) can be used to reduce the
# computational costs of, for example, core excitation energies. In this scheme
# a guess vector for the orbital transition has to be provided. It should be
# used in combination with the davidson method to calculate excitation energies.
# An overlap criterion is used to follow the wanted eigenvector. This key can
# also be used in case of spin-orbit coupling. The use of the key
# SELECTEXCITATION is similar as the use of the key MODIFYEXCITATION. However,
# the key SELECTEXCITATION can not be used in combination with the key
# MODIFYEXCITATION. In the state selective method (key SELECTEXCITATION) the
# one-electron excited state configuration space remains complete, whereas it is
# reduced in case the scheme with the MODIFYEXCITATION key.


$ADFBIN/adf  <<eor
Title Ne

Atoms
  Ne .0000  .0000  0.0000
End

Basis
 Type QZ4P
End

relativistic scalar zora

symmetry d(8h)

NumericalQuality Good

xc
 model SAOP
end

Excitations
 lowest 8
End

eor

mv TAPE21 Frag.t21
rm logfile TAPE21

$ADFBIN/adf -n1 <<eor
Title Ne spin-orbit

Atoms
  Ne .0000  .0000  0.0000  f=Frag
End

relativistic spinorbit zora

symmetry d(8h)

xc
 model SAOP
end

NumericalQuality Good

Excitations
 alsorestricted
 lowest 8
End

Fragments
 Frag Frag.t21
End

STCONTRIB

eor

rm logfile TAPE21

# The difference between the core excitation calculation and the standard
# excitation is the extra subkey MODIFYEXCITATION or SELECTEXCITATION in the
# core excitation calculation (in italic).

# ADF can not handle ATOM and linear symmetries in excitation calculations.
# Therefore a subsymmetry is used, in this case symmetry d(8h).

# A relatively large QZ4P basis set is used, which is still insufficient for
# excitations to Rydberg-like orbitals, one needs more diffuse functions.

# The key STCONTRIB is used, which will give a composition of the spin-orbit
# coupled excitation in terms of singlet-singlet and singlet-triplet scalar
# relativistic excitations. In order to use the key STCONTRIB the scalar
# relativistic fragment should be the complete molecule.

# In this case the key MODIFYEXCITATION or SELECTEXCITATION takes care that only
# excitations from the occupied 1s-orbital (spinor) are included. In symmetry
# d(8H) the 1s-orbital (spinor) is of A1.g (E1/2.g) symmetry.