The structural, electronic and magnetic properties of Ga8-xMnxAs8 clusters

We systematically investigate the ground-state magnetic properties of Ga8-xMnxAs8 clusters (x $=$ 0, 2, 4, 6, and 8) within the framework of density functional theory (DFT) using a strategy that successively adopts the particle swarm optimization (CALYPSO) code and fixed spin-moment (FSM) method. The results show that for Ga8-xMnxAs8 in the ground states or low-lying isomers, Mn atoms tend to assemble at the core of the clusters and the ferrimagnetic Mn-Mn couplings are identified for Ga8-xMnxAs8 (x$=$4, 6, and 8), while Ga8As8 and Ga6Mn2As8 are nonmagnetic. The possibility of multiple ground states of Ga8-xMnxAs8 (x $=$ 4, 6, and 8) is also demonstrated. The binding energy and LUMO-HOMO gap analysis show that Ga8-xMnxAs8 clusters with large x are more likely synthesized and exhibit stronger chemical reactivity.