Regular Article

Formation of rubidium dimers on the surface of helium clusters: a first step through quantum molecular dynamics simulations^★

Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, IFF-CSIC, Serrano 123, 28006 Madrid, Spain

^a e-mail: p.villarreal@iff.csic.es

Received: 13 February 2018
Received in final form: 6 April 2018
Published online: 5 June 2018

Abstract

Starting with separated atoms on the surface of helium clusters ⁴He_N, and as a first step to assess the formation of rubidium dimers Rb₂ in the triplet state, we perform Path Integral Molecular Dynamics simulations in the NVT canonical ensemble. Based on an accurate potential energy surface (PES) for the He–Rb₂(³Σ_u⁺) interaction [Guillon et al., J. Chem. Phys. 136, 174307 (2012)], the total PES is analytically described as the addition of pair interactions. The i-PI code [Ceriotti et al., Comput. Phys. Commun. 185, 1019 (2014)] was used to perform the simulations. At a temperature of 2 K, clusters containing up to N = 70 helium atoms, with a number up to 200 beads per particle to describe quantum effects, were considered.