Exploring rotation-translation coupling for a confined asymmetric rotor using molecular dynamics simulations: the case of the water molecule trapped inside a rare gas matrix. Issue 10 (24th July 2021)

• Record Type: Journal Article
• Authors: Wespiser, Clément; Ayotte, Patrick; Soldera, Armand
• Is Part Of: Molecular simulation. Volume 47:Issue 10/11(2021)
• Page Start: 942
• Page End: 949
• Publication Date: 2021-07-24
• Subjects: Confinement -- matrix isolation spectroscopy -- rotation-translation coupling -- isotopic effects -- molecular dynamics simulations; Molecular dynamics -- Computer simulation -- Periodicals; Statistical mechanics -- Computer simulation -- Periodicals; 539.6
• DOI: 10.1080/08927022.2020.1807019
• Languages: English
• ISSNs: 0892-7022

Abstract

ABSTRACT: Differences between gas-phase and matrix-isolated rotational and rovibrational spectra of the water molecule are interpreted in term of the confined rotor model. The parameters of this model enable the isotopic composition of the molecule, which has non-trivial impacts on the spectra of matrix-isolated confined rotors, to be taken into account on a very simple and intuitive basis. We use molecular dynamics simulations to systematically explore the effects of the mass distribution of various isotopomers of the water molecule on the coupled rotational and translational dynamics of the confined asymmetric rotor, and on their coupling with the phonons of the argon matrix. Analysis of the trajectories reveals that, depending on the mass distribution, a preferred orientation of the water molecule can be strongly imposed by the topology of its interaction potential with the confinement medium. Features of the confining potential, and of the rotation-translation coupling, are thus revealed from classical molecular dynamics simulations.