# Example: Excitation energies including spin-orbit coupling for open shell: PbF¶

Download PbF_excisou.run

Application of a spin-orbit coupled relativistic excitation energy calculation for an open-shell system. Note that the used method used is highly approximate. In this example the effect of spin-orbit coupling is large, in which case this method can be of use.

First a scalar relativistic calculation is performed with symmetry. The resulting scalar relativistic TAPE21 is used as fragment in the spin-orbit coupled calculation. Using a scalar relativistic fragment is not necessary, but makes the identification of the spin-orbit coupled results easier.

$ADFBIN/adf << eor Atoms Pb 0 0 0 F 0 0 2.06 End Basis Type TZ2P Core None End relativistic scalar zora xc gga bp86 end End input eor mv TAPE21 PbF.t21 rm logfile  Next the spin-orbit coupled excitation unrestricted calculation is perfomed. The Tamm-Dancoff approximation (TDA) is needed and symmetry NOSYM should be used. Best is to use the noncollinear approximation. $ADFBIN/adf << eor
Atoms
Pb   0    0   0    f=PbF
F    0    0   2.06 f=PbF
End
Fragments
PbF PbF.t21
End
relativistic spinorbit zora
xc
gga bp86
end
unrestricted
noncollinear
symmetry nosym
tda
excitations
lowest 14
end
End input
eor