Quantum-ionic features in the absorption spectra of homonuclear diatomic molecules

Abstract

We show that additional features can emerge in the linear absorption spectra of homonuclear diatomic molecules when the ions are described quantum mechanically. In particular, the widths and energies of the peaks in the optical spectra change with the initial configuration, mass, and charge of the molecule. We introduce a model that can describe these features and we provide a quantitative analysis of the resulting peak energy shifts and width broadenings as a function of the mass.

Atoms and molecules in cavities, from weak to strong coupling in quantum-electrodynamics (QED) chemistry

“…In the following, we briefly want to discuss the relative coordinates and the real-space grid used for the numerical calculations of section 1. The coordinates are the electron distance coordinate x = x 1 − x 2 , the nuclear distance coordinate X = X 1 − X 2 , the distance between the electronic and the nuclear center of masses ξ and the global center of mass X CM 2 [42]. In this new coordinate system the Hamiltonians of Eqs.…”

“…The complete many-body problem including two electrons, two nuclei and one photon mode is a five-dimensional problem. To reduce the computational complexity, we perform a coordinate transformation into a center-of-mass frame such that the centerof-mass motion can be separated and we are left with a four dimensional problem for the internal degrees of freedom [42]. For details on the transformation and the realspace grid used to perform the numerical calculation, we refer the reader to (SI1).…”