[12a-W834-1~6] 6.5 Surface Physics, Vacuum

△ [12a-W834-4] Investigation of effects of static correlation and spin contamination on DFT calculations for surface reactions

〇Kohei Tada¹, Tomohiro Maruyama², Hiroaki Koga³, Mitsutaka Okumura^2,3, Shingo Tanaka¹ (1.AIST, 2.Osaka Univ., 3.ESICB)

Keywords:density functional theory, Spin contamination error, static correlation

In order to investigate the effects of spin contamination and static correaltion on surface reactions, the aggregation of Au atoms to a Au dimer (Au₂) on a MgO (001) surface was calculated by restricted (spin-un-polarized) and unrestricted (spin-polarized) density functional theory calculations with a plane-wave basis and the approximate spin projection (AP) method. The unrestricted calculations included spin contamination errors of 0.0–0.1 eV, and the errors were removed using the AP method. The potential energy curves for the aggregation reaction estimated by the restricted and unrestricted calculations were different owing to the estimation of the open-shell structure by the unrestricted calculations. These results show the importance of the open-shell structure and correction of the spin contamination error for the calculation of small-cluster-aggregations and molecule dimerization on surfaces.