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