Chemisorptions effect of oxygen on the geometries, electronic and magnetic properties of small size Ni(n) (n = 1-6) clusters.

The present study reports the effect of oxygen addition on small size Ni(n) (n = 1-6) clusters in different spin states within the framework of linear combination of atomic orbital (LCAO) density functional theory (DFT) under spin polarized generalized gradient approximation (GGA) functional. Relative stabilities of the optimized clusters are discussed on the basis of the calculated parameters, such as, binding energy (BE), embedding energy (EE) and fragmentation energy (FE). Other parameters, like ionization potential (IP), electron affinity (EA), etc. show that though the additions of oxygen can affect the chemical properties of Ni(n) clusters with an additional stability to Ni(n)O. In most of the cases the magnetic moment of the stable isomers are geometry dependent for a particular size both in pure and oxidized clusters. Calculated magnetic moments of Ni(n)O (n = 1-6) clusters reveal that the magnetic moment of ground state Ni(4)O isomers in different geometries is same as in pure Ni(4) isomers. Present study also explains the cause of stable magnetic moment in Ni(4)O cluster through the distribution of electrons in different orbitals.