PT3AU AND PTAU CLUSTERS - ELECTRONIC STATES AND POTENTIAL-ENERGY SURFACES

We carried out complete active space multiconfiguration self-consisten t-field calculations followed by multireference singles+doubles config uration interaction with the Davidson correction which included up to 3.55 million configurations employing relativistic effective core pote ntials on Pt-3+Au and PtAu clusters. Four low-lying electronic states were identified for Pt-3+Au. The (2)A(2) electronic state (C-3u) was f ound to be the ground state of Pt,Au. Spin-orbit effects were found to be significant. We also computed six low-lying electronic states of P tAu and four low-lying electronic states of PtAu+. The 5/2 ((2) Delta) and 0(+)((1) Sigma(+)) states were found to be the ground states of P tAu and PtAu+, respectively.