Chemical bonds between noble metals and noble gases. Ab initio study of the neutral diatomics NiXe, PdXe and PtXe

The lowest potential-energy curves are calculated for the species MXe, M = Ni, Pd, Pt. No bound states are found for NiXe. For PdXe the ground state is bound by 41.6 kJ/mol, The PtXe ground-state curve dissociates to an excited Pt(S-1(0)) state but remains bound by 67.9 kJ/mol with respect to the Pt(D-3(3)) ground state. Of this D-e value, 9.2 kJ/mol is due to the stabilization caused by spin-orbit coupling. The calculated quasirelativistic Pt-Xe distance is 242 pm. Both PdXe and PtXe are possible new gas-phase or matrix species. (C) 1998 Elsevier Science B.V. All rights reserved.