# Example: (Core) Excitation energies including spin-orbit coupling: Ne¶

```
#! /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.
AMS_JOBNAME=Frag $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000
end
end
Task SinglePoint
Engine ADF
title Ne
excitations
lowest 8
end
basis
type QZ4P
CreateOutput Yes
end
numericalquality Good
relativity
level scalar
formalism ZORA
end
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
AMS_JOBNAME=Excitations $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000 adf.f=Frag
end
end
Task SinglePoint
Engine ADF
title Ne spin-orbit
excitations
alsorestricted
lowest 8
end
fragments
Frag Frag.results/adf.rkf
end
numericalquality Good
relativity
level spin-orbit
formalism ZORA
end
stcontrib
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
# 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.
```

```
#! /bin/sh
AMS_JOBNAME=Fragmod $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000
end
end
Task SinglePoint
Engine ADF
title Ne
excitations
lowest 8
end
modifyexcitation
useoccupied
A1.g 1
end
usescaledzora
end
basis
type QZ4P
CreateOutput Yes
end
numericalquality Good
relativity
level scalar
formalism ZORA
end
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
AMS_JOBNAME=Excitationsmod $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000 adf.f=Frag
end
end
Task SinglePoint
Engine ADF
title Ne spin-orbit
excitations
alsorestricted
lowest 11
end
fragments
Frag Fragmod.results/adf.rkf
end
modifyexcitation
useoccupied
E1/2.g 1
end
usescaledzora
end
numericalquality Good
relativity
level spin-orbit
formalism ZORA
end
stcontrib
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
AMS_JOBNAME=Fragsel $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000
end
end
Task SinglePoint
Engine ADF
title Ne
excitations
lowest 8
end
basis
type QZ4P
CreateOutput Yes
end
numericalquality Good
relativity
level scalar
formalism ZORA
end
selectexcitation
useoccupied
A1.g 1
end
usescaledzora
end
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
AMS_JOBNAME=Excitationssel $AMSBIN/ams <<eor
System
atoms
Ne .0000 .0000 0.0000 adf.f=Frag
end
end
Task SinglePoint
Engine ADF
title Ne spin-orbit
excitations
alsorestricted
lowest 11
end
fragments
Frag Fragsel.results/adf.rkf
end
numericalquality Good
relativity
level spin-orbit
formalism ZORA
end
selectexcitation
useoccupied
E1/2.g 1
end
usescaledzora
end
stcontrib
symmetry d(8h)
xc
model SAOP
end
EndEngine
eor
```