Structure and properties of B 20 Si −∕0∕+ clusters

A global search for the lowest energy structure of B 20 Si − , B 20 Si 0 and B 20 Si + clusters is conducted. Structural transitions at different charge states are observed. B 20 Si − is a 2D planar configuration with no polygonal holes, and Si atom occupies a peripheral position. B 20 Si + adopts a 3D tubular shape, and each Si is bonded with four B atoms. But for B 20 Si 0 , competition among quasi-planar, tubular and cage like structures is found. These structures differ greatly from that of pure B 21 − cluster. The structural transition may result from changes in the framework of bonding, sp 2 hybridization, and structural mechanics. Some of the clusters’ properties including frontier molecular orbital, on-site charge on Si atom, electron density, and magnetism are also discussed. Graphical abstract