1. Nuclear Materials Technology Division and G. T. Seaborg Institute, Los Alamos National Laboratory, Mail Stop E500, Los Alamos, New Mexico 87545, Chemistry Division, Los Alamos National Laboratory, Mail Stop J514, Los Alamos, New Mexico 87545, Theoretical Division, Los Alamos National Laboratory, Mail Stop B268, Los Alamos, New Mexico 87545, and Laboratoire de Chimie de Coordination, UPR CNRS 8241, 205 Route de Narbonne, 31077 Toulouse Cedex, France