Eur. Phys. J. D (2015) 69: 180
https://doi.org/10.1140/epjd/e2015-60019-6

Regular Article

Quantum description of a rotating and vibrating molecule

Institute of Condensed Matter Physics, Station 3, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

^a e-mail: sylvain.brechet@epfl.ch

Received: 11 January 2015
Received in final form: 27 May 2015
Published online: 23 July 2015

Abstract

A rigorous quantum description of molecular dynamics with a particular emphasis on internal observables is developed accounting explicitly for kinetic couplings between nuclei and electrons. Rotational modes are treated in a genuinely quantum framework by defining a molecular orientation operator. Canonical rotational commutation relations are established explicitly. Moreover, physical constraints are imposed on the observables in order to define the state of a molecular system located in the neighborhood of the ground state defined by the equilibrium condition.