Theoretical study of electronic states of platinum pentamer (Pt5)

Geometries and energy separations of the various low-lying electronic states of Pt5 with different structural arrangements have been investigated. The complete active space multiconfiguration self-consistent-field (CASMCSCF) method followed by large-scale multiconfiguration singles plus doubles configuration interaction (MRSDCI) that included up to 1.64 million configuration spin functions have been used to compute several electronic states. A 1B2 (C2v) electronic state of a distorted tetragonal pyramid equilibrium structure was found to be the minimum energy geometry. We also compared our MRSDCI results with density functional as well as Mo/ller-Plesset second-order perturbation calculations. The dissociation and atomization energies have been computed and the results, together with our previous findings for the smaller Ptn (n=2–4) clusters, were compared with other group 10 member clusters viz., Nin (n=2–5) and Pdn (n=2–5) and the experimental findings.