Time-Dependent Renormalized-Natural-Orbital Theory Applied To Laser-Driven H-2(+)

Recently introduced time-dependent renormalized-natural-orbital theory (TDRNOT) is extended towards a multicomponent approach in order to describe H-2(+) beyond the Born-Oppenheimer approximation. Two kinds of natural orbitals, describing the electronic and the nuclear degrees of freedom are introduced, and the exact equations of motion for them are derived. The theory is benchmarked by comparing numerically exact results of the time-dependent Schrodinger equation for an H-2(+) model system with the corresponding TDRNOT predictions. Ground-state properties, linear-response spectra, fragmentation, and high-order harmonic generation are investigated.