Many-body effects on the structures and stability of Ba2+Xen (n = 1–39, 54) clusters

Abstract

The structures and relative stabilities of mixed Ba(2+)Xe(n) (n = 1-39, 54) clusters have been theoretically studied using basin-hopping global optimization. Analytical potential energy surfaces were constructed from ab initio or experimental data, assuming either purely additive interactions or including many-body polarization effects and the mutual contribution of self-consistent induced dipoles. For both models the stable structures are characterized by the barium cation being coated by a shell of xenon atoms, as expected from simple energetic arguments. Icosahedral packing is dominantly found, the exceptional stability of the icosahedral motif at n = 12 being further manifested at the size n = 32 where the basic icosahedron is surrounded by a dodecahedral cage, and at n = 54 where the transition to multilayer Mackay icosahedra has occurred. Interactions between induced dipoles generally tend to decrease the Xe-Xe binding, leading to different solvation patterns at small sizes but also favoring polyicosahedral growth. Besides attenuating relative energetic stability, many-body effects affect the structures by expanding the clusters by a few percents and allowing them to deform more.

Non-Relativistic Electronic-Structure Computation of Neutral and Cationic Systems [Fr2, Fr–AEM+ (AEM= Ca, Sr, Ba)]

“…After contraction, this number of functions is reduced to 42, 48, 54, and 51; the basis sets become (8s/4p/5d), (8s/5p/5d), (8s/7p/5d), and (8s/6p/5d). These basis sets have given reliable results in other published works. ,,− …”

“…In order to obtain accurate structural and spectroscopic properties within the Born-Oppenheimer approximation, we have adopted the computational scheme successfully applied to the ground and excited states interactions between heteronuclear alkali metal dimers and mixed alkali–AEM ions. − Hence, we have realized a non-relativistic electronic-structure computation of the neutral and cationic systems involving the radioactive atom Fr [Fr 2 , Fr–AEM + (AEM = Ca, Sr, Ba)]. The investigated dissociation limits of Fr 2 homonuclear dimer are {Fr­(7s) + Fr­(7s, 7p, 6d, 8s, 8p)}.…”

Theoretical investigation of the van der Waals interaction in Ba0,+,2+He systems and the stability of Ba2+He n clusters

“…Several theoretical works [2,3,[22][23][24][25][26][27][28][29][30][31] were devoted to the interaction potentials for the ground state of the Ba m+ in rare gas complexes. As an example, Abdessalem and coworkers [29] investigated the many-body effects on the structures and the stability of Ba 2+ Xe n (n=1-34) clusters. The first shell is closed for n=12 corresponding to icosahedral geometry.…”

Computational study of the electronic structure of the Srm+Kr (m = 0, 1) van der Waals complexes

“…In the theoretical scheme, various authors studied the spectroscopic characteristics of the diatomic molecules formed by the metal species [29][30][31][32][33][34][35][36][37][38][39][40]. Tomza and co-workers [38] studied the excited electronic states of the Sr 2…”

“…As an example, Abdessalem et al [34,35] investigated the spectroscopic proprieties and the electric dipole moment (EDM) functions of the Ba + RG and BaRG (RG = Kr, Xe) molecules. These authors [36] studied also the many-body effects on the interaction potentials for the ground state of the Ba m+ in xenon clusters. Moreover, Tang and coworkers [49,50] employed the Tang and Tonnies potential model for the Ca-RG and Sr-RG molecules.…”