Quantum description of a rotating and vibrating molecule

TL;DR

This paper develops a rigorous quantum framework for molecular dynamics, explicitly accounting for kinetic couplings, rotational modes, and physical constraints, providing a detailed quantum description of rotating and vibrating molecules.

Contribution

It introduces a quantum approach to molecular rotation and vibration, including a molecular orientation operator and canonical rotational relations, advancing the theoretical understanding of molecular quantum dynamics.

Findings

Defined a molecular orientation operator with canonical rotational relations

Established quantum constraints for molecular states near equilibrium

Provided a comprehensive quantum description of kinetic couplings in molecules

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.