Exhaustive exploration of MgB (n = 10-20) clusters and their anions.

To understand the effect of magnesium atom doping on boron clusters, here we report the lowest-lying energy structures and electronic properties of neutral and monoanionic magnesium-boron clusters, in which boron atoms range in size from 10 to 20, in the framework of a CALYPSO structural search and DFT calculations. One of the most stable combinations is MgB18, which adopts an unexpected tubular drum-shaped geometry that is found for the first time in boron clusters doped with alkaline-earth metal atoms. The stability of the MgB18 cluster mainly stems from the intense electrostatic interaction between the B18 skeleton and the Mg atom.