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In this paper, we used CALYPSO program which is conjuncted with DFT to investigate Li doped small-sized neutral Bn clusters. From ground-state and low energy structures, the properties and geometric significance of Li-doped boron clusters are greatly affected. Except for LiB9, which adds a B atom on preceding LiB8 boron wheel, the ground-state clusters of LiBn are formed by replacing the terminal boron atom of the Bn+1 clusters in the same size with a Li atom or by adding a Li atom to the Bn clusters. The transition point from 2 to 3D configuration of LiBn clusters appears at n = 5. The stability of LiBn clusters was analyzed by calculating the average binding energy, Gibbs free energy, first-order differential energy, second-order differential energy, HOMO–LUMO gap (the energy gap between the highest occupied and lowest unoccupied molecular orbital) and charge transfer. The results show that the LiB11 cluster with excellent symmetry and planar structure is the relative most stable structure. Molecular orbital and chemical bonding analysis indicated that the main reason for the stability of the LiB11 cluster is mainly due to the strong s-p bonding of B–B. [ABSTRACT FROM AUTHOR]

[Display omitted] • The evolution of the structures for Ba 2 Mg n (n = 1–10) clusters has be elucidated. • The corresponding ground state structures are determined. • A pagoda-like most-stable structure are found. • The properties of electrons and bonds of the most stable isomers are discussed. This paper reports systematic studies of small sized magnesium clusters doped with two barium atoms in both neutral and anionic species. The search, geometric optimization, and energy correction of stable and low-energy structures were completed using CALYPSO software package and DFT calculations. The structural evolution of Ba 2 Mg n 0/– clusters (n = 1–10) with increasing size were elucidated, and we found that most of the ground-state isomers of them inherit that of the corresponding pure Mg clusters well in terms of structure. After verifying the NBO (natural bond orbital) charge of the low-lying Ba 2 Mg n 0/– clusters (n = 1–10), a new fact was exposed: that all the doped Ba atoms in the structures are positively charged except in Ba 2 Mg–. A pagoda-like most-stable cluster Ba 2 Mg 8 with a HOMO-LUMO gap of 1.59 eV was found by relative stability analysis within the scope of our study. Further analyses of the molecular orbitals and bonding of Ba 2 Mg 8 clusters also revealed a strong interaction between Ba-6 s and Mg-3 p AOs, which may be the main reason for the high stability of Ba 2 Mg 8. We hope our studies will provide guidance for the synthesis and application of doped Mg-based nanomaterials in the future. [ABSTRACT FROM AUTHOR]

• The evolution of the structures for Ba n Mg m 0/– (n = 1,2; m = 10–15) clusters has be elucidated. • The corresponding ground state structures are determined. • Two local stable ground state structures are found. • The properties of electrons and bonds of the most stable isomers are discussed. Projects about alkaline-earth metals doped magnesium are hot issues constantly in cluster science, while research in terms of Mid-Sized Ba atoms doped magnesium cluster was unreported. We adopted the CALYPSO method coupled with DFT calculation to simplify the process of structure searching at the range of Ba n Mg m 0/– (n = 1,2; m = 10–15) cluster. We found the doped Ba atoms tend to occupy convex capped sites in each structure. Meanwhile, the six-atom triangular prism as a major structure constructed the great mass of isomers. Based on the result of the relative stability survey, we selected BaMg 13 – and Ba 2 Mg 13 – to conduct further investigations, according to a different numbers of doped Ba atoms. Analysis of the bonding character manifests that the Mg- p orbital takes up the highest proportion for both BaMg 13 – and Ba 2 Mg 13 – cluster at HOMO, LUMO position as well as the existence of strong covalent bonds between Mg-Mg atoms and Ba-Mg atoms. [Display omitted] [ABSTRACT FROM AUTHOR]