Coupling electrons and vibrations in molecular quantum chemistry
Abstract
We derive an electron-vibration model Hamiltonian in a quantum chemical framework, and explore the extent to which such a Hamiltonian can capture key effects of nonadiabatic dynamics. The model Hamiltonian is a simple two-body operator, and we make preliminary steps at applying standard quantum chemical methods to evaluating its properties, including mean-field theory, linear response, and a primitive correlated model. The Hamiltonian can be compared to standard vibronic Hamiltonians, but is constructed without reference to potential energy surfaces, through direct differentiation of the one- and two-electron integrals at a single reference geometry. The nature of the model Hamiltonian in the harmonic and linear-coupling regime is investigated for pyrazine, where a simple time-dependent calculation including electron-vibration correlation is demonstrated to exhibit the well-studied population transfer between the S and S excited states.
Keywords
Cite
@article{arxiv.2010.04654,
title = {Coupling electrons and vibrations in molecular quantum chemistry},
author = {Thomas Dresselhaus and Callum B. A. Bungey and Peter J. Knowles and Frederick R. Manby},
journal= {arXiv preprint arXiv:2010.04654},
year = {2021}
}