Example: Excitation energies and polarizability: Au2¶
A calculation of response properties of the Au2 dimer, with ZORA relativistic corrections
$ADFBIN/adf << eor Title Au2, Response Properties XC GGA LB94 End Relativistic Scalar ZORA Atoms Au 0.0 0.0 1.236 Au 0.0 0.0 -1.236 End Basis Au ZORA/DZ/Au.4d End Symmetry D(8h) Excitations Lowest 10 TOLERANCE 1d-10 End Response AllComponents End End Input eor
In the response module infinite symmetries cannot be handled (see the User’s Guide), so we specify a lower subgroup in the input file, here D(8h).
In this sample run the LB94 potential is used. The implementation implies that the XC potential is evaluated from the exact charge density, rather than the cheaper and faster fitted density (as is the case for other XC functionals). This means that the computation times are longer. In a small molecule like Au2 this hardly shows, but in larger molecules the differences may be more significant. Note that the LB94 is a model potential, thus the calculated bond energy has not so much meaning. If the BASIS key is used and the model potential LB94 in the create run of the atoms the BP86 functional is used.
Excitation energies are computed, in principle the lowest 10 in each irrep of the symmetry (see, however, the User’s Guide).