Probing the Structural Evolution and Stabilities of LiB_n^- (n=2-12) Clusters

In this study, the crystal structure analysis by particle swarm optimization (CALYPSO) was used to search the structure of negative LiBn- (n = 2-12) clusters, and the corresponding ground-state structures and low energy isomers were determined. Based on the predicted ground state structures, the doped Li atom has little modification on B-n(-) skeleton, which can be seen from the charge analysis that it is caused by the transfer of electron from dopant to B-n(-) part. The photoelectron spectroscopy (PES) simulations were conducted using time-dependent density functional theory (TD-DFT). By analyzing the stability, we find LiB8- cluster with high symmetry C-7V with ideal stability, and it has a classic umbrella structure. Deep analysis of the bonding characteristics of the LiB8- cluster shows that the B-B covalent bonds in the B-8(-) part and the electrostatic interaction between the B-8(-) wheel and the Li atom stabilize the LiB8- cluster.