Small ternary AlnBmHl clusters: DFT analysis of structure and properties

Abstract

Using a stochastic multistep algorithm, a systematic search for the lowest energy structures and different isomeric forms of atomic AlnBmHl clusters with n + m ≤ 4 (n ≥ 1, m ≥ 1) and all possible values of l are accomplished. Their energetics and numerous physical properties are determined within the density functional theory approach (B97-2 functional). Basic temperature-dependent thermodynamic functions are calculated both for each obtained isomer and for equilibrium ensembles of isomers of clusters with fixed atomic composition taking into consideration the anharmonicity of vibrations and the role of excited electronic states. The corresponding data are fitted to seven-parameter NASA (Chemkin) polynomials. The properties of small aluminoborane clusters are discussed from the point of view of their application in hydrogen storage and energetic materials.