Eur. Phys. J. D (2016) 70: 242
https://doi.org/10.1140/epjd/e2016-70147-0

Regular Article

Structure and stability of Na⁺Xe_n clusters

¹ Laboratoire d’Études des Milieux Ionisés et Réactifs (EMIR), Institut Préparatoire aux Études d’Ingénieurs de Monastir, Monastir, 5000, Tunisia
² Laboratoire de Chimie et de Physique Quantiques, IRSAMC, Université de Toulouse (UPS) and CNRS, Université Paul Sabatier, 118 roue de Narbonne, 31062 Toulouse, France

^a e-mail: fernand.spiegelman@irsamc.ups-tlse.fr

Received: 29 February 2016
Received in final form: 15 July 2016
Published online: 17 November 2016

Abstract

The structure and stability features of Na⁺Xe_n (n ≤ 54) clusters are theoretically investigated via model potential energy surfaces (PES) and unconstrained global optimization. The potential energy is described in terms of pair-additive potentials including polarization parametrized from accurate ab initio data on Na⁺Xe, complemented by three-body contributions describing the interaction between the dipoles induced by the sodium ion on the rare gas atoms. We show that the three-body contributions stabilize the linear or planar structures versus more compact shapes for n< 4. At larger sizes, the growth around the square antisprism (SA) or capped square antisprism (CSA) core is favored while icosahedral pattern based isomers exist but not as the lowest ones. A transition in the metal ion coordination from 8 (square antiprism) to 12 (icosahedron) is seen to occur near n = 50. The results are discussed and analyzed in view of existing accurate ab initio calculations on Na⁺Xe₂ and comparisons with similar metal-ion clusters.