SCM: Examples

Ne: (core) excitation energies including spin-orbit coupling

Sample directories: adf/Ne_exciso/ and adf/Ne_CoreExci/

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

$ADFBIN/adf << eor
Title Ne
Atoms
  Ne .0000  .0000  0.0000
End
Basis
 Type QZ4P
End
relativistic scalar zora
symmetry d(8h)
integration 6.0
xc
 model SAOP
end
Excitations
 lowest 10
End

 ModifyExcitation
   UseOccupied
    A1.g 1
   SubEnd
   UseScaledZORA
  END

End input
eor

mv TAPE21 Frag.t21
rm logfile TAPE21

$ADFBIN/adf << eor
Title Ne spin-orbit
Atoms
  Ne .0000  .0000  0.0000  f=Frag
End
relativistic spinorbit zora
symmetry d(8h)
xc
 model SAOP
end
integration 6.0
Excitations
 lowest 12
End

  ModifyExcitation
   UseOccupied
    E1/2.g 1
   SubEnd
   UseScaledZORA
  END

Fragments
 Frag Frag.t21
End
STCONTRIB
End input
eor

The difference between the core excitation calculation and the standard excitation is the extra subkey MODIFYEXCITATION 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 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.

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