Structure and Stability of the Li+Xen and LiXen Clusters

Abstract

We have studied the structure and stability of the ionic Li ? Xe n and neutral LiXe n (n = 1-35) small clusters. The potential energy surface of the ionic cluster is described using additive potentials, which represent the pair interactions taken from the best available coupled cluster ab initio calculations. The V Li ? Xe and V Xe-Xe potentials have been fitted by Tang and Toennies and Lennard-Jones (LJ) forms, respectively. The structure of LiXe n neutral clusters have been investigated using a model potential and ab initio calculations. We have used the Li ? Xe potential in its ground state and fitted to the Tang and Toennies formula. The LiXe n optimized geometry is, then, used for one electron self consistent filed calculation of the only alkali valence electron interacting with the Li ? Xe n cluster. In order to determine the geometry of Li ? Xe n and LiXe n clusters and their isomers, the potential energy surface has been explored by the Monte Carlo basin Hopping method. Their relative stability was studied by evaluating the energy and the energy differences as function of number n of Xenon atoms in clusters. It was shown, for Li ? Xe n , that n = 4, 6,10,14,16,18,20,22,24, 26, 28 and 30 are the most stable structures.

Atomic Gold Ions Clustered with Noble Gases: Helium, Neon, Argon, Krypton, and Xenon

“…For example, the structure and stability of alkali ions (Li + , Na + , K + and Cs + ) solvated in xenon has been explored by different theoretical approaches. [64][65][66][67] The calculated dissociation energies do not feature enhanced binding at n = 2, even if pairwise additive potentials are augmented by three-body contributions that account for the interaction between the dipoles induced by the ion on the noble gas atoms.…”

“…These trends have been confirmed in various experimental studies, for example, for Na + , Al + , and In + , for K + and Mg + , Li + , and Cu + solvated in various noble gases. Support also comes from theoretical studies employing more realistic two- or three-body potentials for the ion–ligand and ligand–ligand interactions, for example, for different alkali ions solvated in xenon. − …”

“…It is tempting to conclude that the bond in NeAu + and Ne 2 Au + is not entirely physical, contrary to conclusions drawn in previous studies. ,, A comparison with alkali ions solvated in noble gases, which are model systems for purely physical bonding, is instructive. For example, the structure and stability of alkali ions (Li + , Na + , K + , and Cs + ) solvated in xenon have been explored by different theoretical approaches. − The calculated dissociation energies do not feature enhanced binding at n = 2, even if pairwise additive potentials are augmented by three-body contributions that account for the interaction between the dipoles induced by the ion on the noble-gas atoms.…”

Helium Droplet Mass Spectrometry

“…The bond nature of AuRg m + (m = 1, 2) is predicted to exhibit significant covalent character for Rg = Kr and Xe, slight covalent character for Ar [319,329,[333][334][335], but to be entirely physical for Ne [328,333,335]. Alkali metal ions embedded in rare gas clusters A + Rg m , can be used as an entirely physically bound model system, but no anomalies at m = 2 can are predicted for A = Li-K and Rg = Ar, Xe [336][337][338][339]. It is conceivable that the theoretical treatment of AuNe m + is inaccurate, failing to reproduce the observed anomaly at m = 2, which might also infer that the character of binding in AuNe m + is not entirely physical in the end.…”

Solvation of Isoelectronic Halide and Alkali Metal Ions by Argon Atoms

“…For example, a broad range of experimental and theoretical studies have examined singly charged alkali metal cations in this context (M + Ng n , where M = Li, Na, K, etc. ). − In contrast, fewer investigations of their isoelectronic halide anion counterparts (X – Ng n , where X = H, F, Cl, etc. ) have been reported, particularly for n ≥ 3. − …”