Search

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]

In this paper, the geometric structure and physicochemical properties of Li2Bn0/− (n = 1–12) clusters were investigated using CALYPSO structure prediction software in combination with density functional theory at B3LYP/6-311G level. The results suggest that the doping of Li atoms has a significant effect on the ground state geometry of the Bn clusters. The stability changes with the increase in the number of boron atoms. Then two stable ground state structures, Li2B8 and Li2B9−, are selected for further analyzing their molecular orbitals and bonding properties. It is demonstrated that the stability of the Li2Bn0/− (n = 1–12) clusters originates from the s–p hybridization between B–B and Li–B. It is expected that this work can provide some references for future research on boron-based nanomaterials. [ABSTRACT FROM AUTHOR]

Projects about magnesium-based doped of transition metal have constantly attracted much attention in cluster science, while the research of Co, Fe, Ni doped Mid-Sized Mg16 clusters has not been reported. Here, the geometric construction and electronic properties of neutral and negative Mg16X (X = Co, Fe, Ni) clusters were researched by unbiased CALYPSO structure search codes and subsequent DFT calculations at the B3PW91 level. The results show that Fe and Co atoms are more likely to replace the central bits of the caged Mg170/− cluster, but the excellent and stable configuration of the Mg170/− cluster is perfectly maintained. Simultaneously, the doping of Co and Fe can cause the cluster to produce the corresponding magnetic moment. The caged Mg16Co− clusters with a central Co atom have good binding energy, local charge transfer and HOMO–LUMO gap according to stability analysis, which indicates that Mg16Co− clusters has better relative stability. In addition, it is found that there is an intense interaction between Mg-3s, p and Co-3d AO (molecular orbitals) through the analysis of molecular orbitals and adaptive natural density partitioning (AdNDP), which may be the main reason for the high stability of Mg16Co− clusters. [ABSTRACT FROM AUTHOR]

Divalent metal clusters, such as alkaline-earth metal clusters, have drawn extensive attention because of the appealing size-evoked nonmetal-to-metal transition and attractive characters related to the size, shape, and doping of clusters. Herein, the structural properties of small-size neutral and anionic Mgn+1 and BaMgn (n = 2–10) clusters are investigated thoroughly through a combination of the CALYPSO software package and DFT optimization. The final calculation results indicate that with the increase in Mg atom number, Ba atoms are inclined to substitute Mg atoms located at the skeleton convex cap. What is worth mentioning is that BaMg9 cluster which presents tower framework possesses excellent stability in specified size range on account of the detailed analysis of bond energy, second-order energy difference, and the charge transfer. In addition, the analysis of the bonding characteristics manifests that the strong s–p interaction between Ba and Mg atomic orbitals is conducive to the improvement in the stability of BaMg9. [ABSTRACT FROM AUTHOR]