Semiclassical “Divide-and-Conquer” Method for Spectroscopic Calculations of High Dimensional Molecular Systems

We present a new semiclassical “divide-and-conquer” approach tailored for quantum dynamics simulations of high dimensional molecular systems.[1] We show how the method is tested by calculating the quantum vibrational power spectra of water, methane and benzene, three molecules of increasing dimensionality for which benchmark quantum results are available. Then, we applied it to C60 fullerene, a system characterized by 174 vibrational degrees of freedom. Results show that the approach accurately account for quantum anharmonicities, purely quantum features like overtones, and the method does not suffer from the removal of degeneracy when the molecular symmetry is broken. Applications for nH2-protonated glycine and I2 in liquid Kr will be reported. [1] M. Ceotto, G. Di Liberto, and R. Conte, “Semiclassical “Divide-and-Conquer” Method for Spectroscopic Calculations of High Dimensional Molecular Systems”, Phys. Rev. Lett. 119, 010401 (2017);