Oxidation of Ni13 clusters

We perform ab initio calculations to investigate Ni-13 clusters reaction under an oxygen atmosphere. We dynamically evaluate the effect on structural, electronic, and magnetic properties for pristine and oxidated clusters. As oxygen chemisorption increases, the pristine icosahedral cluster tends to adopt a cubic sodium chloride configuration, resistant to further oxidation. Although each chemisorbed O atom draws one electron, the cluster magnetization stays in the 4-8 mu(B) range, with magnetic moment localized at Ni atoms. Oxygen effect on the electronic structure is to hybridize O(p) - Ni(s, d) among low-lying occupied states and to induce a HOMO-LUMO gap opening, while also shifting downwards the electronic band edges, making them favorably aligned with photocatalytic reactions.