SPIN-ORBIT EFFECTS IN THE PTH2+ ION

The five low-lying doubler states of PtH2+ have been studied by all-el ectron one- and two-component variational calculations using the Dougl as-Kroll operator in a RASCI formalism. CASSCF calculations are perfor med in order to optimize orbitals for the subsequent RASCI calculation s. Spin-orbit effects are introduced on the CI level both as a perturb ation based on the spin-free CI states and variational in spin-orbit R ASCI calculation. The influence of thr: spin-orbit effects are studied on geometries, excitation energies, reaction barrier and dissociation energies. (C) 1998 Elsevier Science B.V. All rights reserved.