Study on structures and electronic properties of NaxV (x=1-12) atomic clusters

Superatoms, novel entities being studied extensively in recent years, can be stabilized by mixing with transition metal atoms. The aim of this paper is to present some recent theoretical results on the application of quantum calculations for examining the atomic clusters NaxV (x=1-12) made from the mixing of Nax superatoms with vanadium transition metal atom. Optimized structures of NaxV, NaxV+ and NaxV- are determined by using the TPSSTPSS / DZVP DFT calculations. Characteristics of optimized structures, as point group symmetry, chemical hardness (η), absolute electronegativity (χ), electrophilicity index (ω), fragmentation energy (Ef), secondary energy (∆2E), are calculated. The obtained results point out that among different structures of an atomic cluster, the more negative total energy the more stable structure and the Na8V cluster is the most stable in NaxV (x=1-12) clusters.

Unstable Triple Systems - Escape From Initial Configurations

The statistical material obtained at the Leningrad observatory amounts to about 3, 104 tripe systems with negative total energy (Anosova and Orlov, 1985; Anosova 1986). From this material the basic qualitative results have been summarized.

Review of the Dynamical Aspects of Triple Systems

A classification of possible motions of triple systems is presented emphasizing the transient phenomena occurring in addition to the final (asymptotic) outcome and clarifying the discrepancies between the astronomical and mathematical formulations. A conjectured possible instability is described and it is shown that systems with negative total energy and low angular momentum may lead to instability and to the formation of binaries. The ejected or escaping star may have high velocity if the triple close approach preceding the escape is sufficiently close. The computational results of several systematic series of such escapes are applied to various stellar configurations.The present status of the fundamental problem of partitioning the phase-space into stable and unstable regions is reviewed and a recently developed technique, applicable to stellar dynamics is described. Recently discovered families of periodic orbits and previously established classical configurations are shown to weaken the general instability conjecture.The possible existence of triple systems in states of dissolution offer intriguing observational challenges regarding the discovery of these projected temporary trapezium type systems.