TiCl₄: core excitation energies

Sample directory: adf/TiCl4_CoreExci/

Calculation of the 2p Ti and 2p Cl core excitation energies of TiCl₄

$ADFBIN/adf << eor
Title TiCl4 TD-DFT scalar relativistic 2p Ti core excitations

Units
 LENGTH BOHR
End

Atoms
 Ti 0.       0.        0.    
 Cl    2.36754     2.36754     2.36754   
 Cl   -2.36754    -2.36754     2.36754   
 Cl    2.36754    -2.36754    -2.36754   
 Cl   -2.36754     2.36754    -2.36754   
End
SYMMETRY T(D)  

EPRINT
 eigval 1000 1000
End

XC
 GGA LB94
End

relativistic scalar zora

ModifyExcitation
 UseOccupied
  T2 2
 SubEnd
 UseScaledZORA
END

Excitation
 ONLYSING
 Davidson &
  T2 12
 SubEnd
End

Basis
 Type DZ
 Core None
End

end input
eor

In this example, the 12 lowest singlet-singlet excitation energies of T₂ symmetry are calculated, the dipole allowed excitations. This can also be achieved using the ALLOWED subkey in the key Excitation.

In this example only excitations from the 2t₂-orbital are included (see the key MODIFYEXCITATION), an almost pure 2p core orbital of titanium. The orbital energies of the uninteresting other occupied orbitals are artificially changed to a large negative value (-1d6 hartree).

In the second example the 2p Cl core excitation energies of TiCl₄ are calculated. The difference between the first example in this one is mainly the use of the key MODIFYEXCITATION:

ModifyExcitation
 UseOccRange -8.0 -6.0
 UseScaledZORA
END

In this example only excitations from occupied orbitals are considered which have orbital energies between -8 and -6 hartree, namely the 5a₁, 1e, 1t₁, 4t₂, and 5t₂ orbitals, which are almost pure 2p core orbitals of chlorine. The orbital energies of the uninteresting other occupied orbitals are again artificially changed to a large negative value (-1d6 hartree).