Q.
Excited states of transition metal complexes
A. In our
experiences, the following basis sets work very nicely for the excited states
of tetraoxo-transition metal complexes and
photochemistry of Ni(CO)4. Our recommendation is the valence
double-zeta set plus double polarization p-function for the central metal and
the double-zeta set for the ligand atoms. In Ni(CO)4, [6s2p2d/4s2p] set was augmented with
double polarization p-function for the Ni atom and with Rydberg
s and p functions for the C and O atoms (J. Chem. Phys. 103, 6993-6998 (1995)).
In TcO42-, [7s3p3d/4s2p] set was augmented with double
polarization p-function for the Tc atom (Theoret. Chim. Acta, 92,
351-359 (1995)). Please find more details in the original papers and the
references therein. Use of ECP is not recommended (J. Chem. Phys., 97,
2561-2570 (1992)).