Looking forward, the present method should be applicable to realistic, ab initio systems, which we will report in a future publication. We also anticipate running fewest switches surface hopping (FSSH) calculations in the future where we will studying molecules moving (adiabatically or nonadiabatically) along metal surfaces once a gradient 53 has been constructed; obviously, studying electrochemical dynamics will be easier than studying photoelectrochemical dynamics. Finally, in this paper, by working with a model Hamiltonian, we have ignored the question of electron-electron exchange that inevitably complicates any description of a metal (where Hartree-Fock exchange is not physical). In the future, when working with realistic (fully ab initio) models of molecules on surfaces, it would be very helpful if we can merge the present CASSCF(2,2) wavefunction calculation with a DFT framework, either in the spirit of multiconfiguration pair-density functional theory (MC-PDFT), time-dependent density functional theory plus one double (TDDFT-1D), or hole-hole Tamm-Dancoff approximated (hh-TDA). Armed with such an algorithm, one anticipates many new calculations that one would like to tackle at a catalytic metal surface.