Theoretical investigation of the interaction between oxygen molecules and small Au clusters using approximately spin-projected geometry optimization (AP-opt) method

The effects of spin contamination errors in the optimized geometry of oxygen-adsorbed Au cluster model systems were examined by using broken symmetry geometry optimization (BS-opt) and an approximate spin-projected broken symmetry geometry optimization (AP-opt) method combined with the hybrid density functional (B3LYP) method. The AP-opt method effectively eliminated spin contamination errors from the BS-opt calculations of optimized geometry and energy of Aun–O2 (n = 1, 2 and 13) model systems.