Exact quantum dynamics developments for floppy molecular systems and complexes

Abstract

[EN]Molecular rotation, vibration, internal rotation, isomerization, tunneling, intermolecular dynamics of weakly and strongly interacting systems, intra-to-inter-molecular energy transfer, hindered rotation and hindered translation over surfaces are important types of molecular motions. Their fundamen- tally correct and detailed description can be obtained by solving the nuclear Schr¨odinger equation on a potential energy surface. Many of the chemically interesting processes involve quantum nu- clear motions which are ‘delocalized’ over multiple potential energy wells. These ‘large-amplitude’ motions in addition to the high dimensionality of the vibrational problem represent challenges to the current (ro)vibrational methodology. A review of the quantum nuclear motion methodology is provided, current bottlenecks of solving the nuclear Schr¨odinger equation are identified, and solu- tion strategies are reviewed. Technical details, computational results, and analysis of these results in terms of limiting models and spectroscopically relevant concepts are highlighted for selected numerical examples.