Properties of neutral and charged cobalt-doped arsenic CoAsn(0±1) (n = 1–15) clusters by density functional theory

Abstract

The structural, electronic and magnetic properties of neutral and charged CoAsn (n=1–15) have been systematically investigated using spin polarized density functional theory to highlight the effects of a cobalt atom on properties of arsenic clusters. Compared with the neutral clusters, the ground state structures of CoAsn+ and CoAsn− were obviously rearranged due to the extraction or the addition of an electron. The optimized clusters reveal that the most stable structures and their corresponding isomers have three dimensional configurations. The relative stabilities have been studied in terms of the binding energies, fragmentation energies and second-order difference of energies for all CoAsn(0±1) structures. The values of HOMO–LUMO gaps have a decreasing tendency along with the increasing number of As atoms in the cluster. The HOMO–LUMO gaps decrease considerably in doped clusters which suggest an increase of metallic property. Total magnetic moment depends on the geometry, the position of Co atom in the cluster, the charge transfer and orbital hybridization. The vertical ionization potential (VIP), vertical electronic affinity (VEA), chemical hardness (η), adiabatic electronic affinity (AEA) and adiabatic ionization potential (AIP) have also been investigated and discussed.