Virial theorem decomposition of potential-energy surfaces. Analysis of the double many-body expansion ground-state surface of Li3

Abstract

The virial theorem is used to decompose selected cuts of a recently reported double many-body expansion (DMBE) potential-energy surface for the ground state of Li₃ into the electronic kinetic and potential components. 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 changes of the respective electronic-energy components in such processes. Their physical interpretation is given in terms of the bond breaking–bond forming mechanism. Illustrative uniform scaling cuts are used to verify the relevant integral virial theorem constraints.