Li2B12 and Li3B12: Prediction of the Smallest Tubular and Cage-like Boron Structures

摘要

An intriguing structural transition from the quasi-planar form of B-12 cluster upon the interaction with lithium atoms is reported. High-level computations show that the lowest energy structures of LiB12, Li2B12, and Li3B12 have quasi-planar (C-s), tubular (D-6d), and cage-like (C-s) geometries, respectively. The energetic cost of distorting the B-12 quasi-planar fragment is overcompensated by an enhanced electrostatic interaction between the Li cations and the tubular or cage-like B-12 fragments, which is the main reason of such drastic structural changes, resulting in the smallest tubular (Li2B12) and cage-like (Li3B12) boron structures reported to date.