VIRIAL-THEOREM DECOMPOSITION OF POTENTIAL-ENERGY SURFACES - ANALYSIS OF THE DOUBLE MANY-BODY EXPANSION GROUND-STATE SURFACE OF LI3

The virial theorem is used to decompose selected cuts of a recently re ported double many-body expansion (DMBE) potential-energy surface for the ground state of Li3 into the electronic kinetic and potential comp onents. Two-dimensional cuts include the fixed-angle atom-exchange and the atom-fixed-diatomic potential. Similar partitionings of the two- and three-body terms are also reported. Examining one-dimensional cuts along the minimum-energy and the uniform-scaling paths reveals change s of the respective electronic-energy components in such processes. Th eir physical interpretation is given in terms of the bond breaking-bon d forming mechanism. Illustrative uniform scaling cuts are used to ver ify the relevant integral virial theorem constraints.