https://doi.org/10.1140/epjd/e2016-70147-0
Regular Article
Structure and stability of Na+Xen 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
The structure and stability features of Na+Xen (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.
Key words: Clusters and Nanostructures
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2016