Electronic Structure for Multielectronic Molecules near a Metal Surface

We analyze a model problem representing a multielectronic molecule sitting on a metal surface. Working with a reduced configuration interaction Hamiltonian, we show that one can extract very accurate ground state wave functions as compared with numerical renormalization group theory (NRG) - even in the limit of weak metal-molecule coupling strength but strong intramolecular electron-electron repulsion. Moreover, we extract what appear to be meaningful excitation energies as well. Our findings should lay the groundwork for future ab initio studies of charge transfer processes and bond making/breaking processes on metal surfaces.