LiB₁₃: A New Member of Tetrahedral-Typed B₁₃ Ligand Half-Surround Cluster

It will get entirely unusual derivatives with gratifying chemical bonding schemes for boron clusters by doping with lithium, the lightest alkalis. The geometric structures and electronic properties of the LiB_n^0/- (n = 10-20) clusters have been studied through Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) structural search approach along with the density functional theory (DFT) calculations. The low-lying candidates of LiB_n^0/- (n = 10-20) are reoptimized at the B3LYP functional in conjunction with 6-311 + G(d) basis set. Three forms of geometric configurations are identified for the ground-state structures of LiB_n^0/- clusters: half-sandwich-type, quasi-planar and drum-type structures. The photoelectron spectra (PES) of the LiB_n^- clusters have been calculated through time-dependent density functional theory (TD-DFT). A promising LiB₁₃ with tetrahedral-typed B₁₃ ligand half-surround cluster and robust stability is uncovered. The molecular orbital and adaptive natural density partitioning (AdNDP) analysis show that B-B bonds in the B₁₃ moiety combined with the interaction between the B₁₃ shell and Li atom stabilize the C_2v LiB₁₃ cluster. Our results advance the fundamental understanding about the alkali metal doped boron clusters.