Example: X-Ray Absorption and Emission Quadrupole Oscillator strengths at the Cl K-edge: TiCl4¶
Calculation of the 1s Cl core excitation energies of TiCl4. Both X-Ray Emission (XES keyword) and X-Ray absorption (XAS keyword in EXCITATION key) are calculated. The individual (zeroth and higher order) oscillator strength components to the total oscillator strengths will be printed (ALLXESQUADRUPOLE, ALLXASQUADRUPOLE).
In order to calculate a 1s-orbital that is localized on one of the Cl atoms, a frozen core approach is used on the other Cl atoms, such that there is only one Cl 1s-orbital, which will remain localized in the molecule.
In order to get information of the population analysis on all core orbitals, a large negative value was included as argument for the orbpoper subkey of the block key EPRINT. This orbital analysis shows that the 2 A1 orbital is indeed the 1s Cl orbital, see subkey corehole of block key XES, and subkey useoccupied of block key MODIFYEXCITATION.
$ADFBIN/adf << eor
TITLE TiCl4 X-Ray Absorption and Emission Quadrupole Oscillator strengths at the Cl K-edge
ATOMS
1 Ti 0.0000 0.0000 0.0000
2 Cl 0.0000 0.0000 2.2930
3 Cl.1 1.0809 -1.8722 -0.7643
4 Cl.1 -2.1618 0.0000 -0.7643
5 Cl.1 1.0809 1.8722 -0.7643
END
SYMMETRY C(3V)
BASIS
type TZP
core None
createoutput None
Cl.1 $ADFRESOURCES/TZP/Cl.2p
END
XC
GGA Becke Perdew
END
EPRINT
eigval 1000 1000
orbpoper -10000 100
End
RELATIVISTIC Scalar ZORA
XES
COREHOLE A1 2
ALLXESQUADRUPOLE
END
MODIFYEXCITATION
UseOccupied
A1 2
SubEnd
END
EXCITATION
Davidson
ONLYSING
lowest 10
XAS
ALLXASQUADRUPOLE
END
end input
eor
In the second example, to test gauge dependency, the molecule is shifted 100 Angstrom in the z-direction.
ATOMS
1 Ti 0.0000 0.0000 100.0000
2 Cl 0.0000 0.0000 102.2930
3 Cl.1 1.0809 -1.8722 99.2357
4 Cl.1 -2.1618 0.0000 99.2357
5 Cl.1 1.0809 1.8722 99.2357
END