Eur. Phys. J. D (2014) 68: 80
https://doi.org/10.1140/epjd/e2014-40217-6

Regular Article

Structure and stability of small Li₂⁺(X²Σ⁺_g)-Xe_n (n = 1–6) clusters

¹ Laboratoire des Interfaces et Matériaux Avancés, Département de Physique, Faculté des Sciences, Université de Monastir, 5019 Monastir, Tunisia
² Physics Department, College of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia

^a e-mail: hamid.berriche@fsm.rnu.tn

Received: 9 April 2013
Received in final form: 20 December 2013
Published online: 23 April 2014

Abstract

We have studied the structure and stability of the Li₂⁺(X²Σ⁺_g)Xe_n (n = 1–6) clusters for special symmetry groups. The potential energy surfaces of these clusters, are described using an accurate ab initio approach based on non-empirical pseudopotential, parameterized l-dependent polarization potential and analytic potential forms for the Li⁺Xe and Xe-Xe interactions. The pseudopotential technique has reduced the number of active electrons of Li₂⁺(X²Σ⁺_g)-Xe_n (n = 1–6) clusters to only one electron, the Li valence electron. The core-core interactions for Li⁺Xe are included using accurate CCSD(T) potential fitted using the analytical form of Tang and Toennies. For the Xe-Xe potential interactions we have used the analytical form of Lennard Jones (LJ_{6 - 12}). The potential energy surfaces of the Li₂⁺(X²Σ⁺_g)Xe_n (n = 1–6) clusters are performed for a fixed distance of the Li₂⁺(X²Σ⁺_g) alkali dimer, its equilibrium distance. They are used to extract information on the stability of the Li₂⁺(X²Σ⁺_gXe_n (n = 1–6) clusters. For each n, the stability of the different isomers is examined by comparing their potential energy surfaces. Moreover, we have determined the quantum energies (D₀), the zero-point-energies (ZPE) and the ZPE%. To our best knowledge, there are neither experimental nor theoretical works realized for the Li₂⁺(X²Σ⁺_gXe_n (n = 1–6) clusters, our results are presented for the first time.