Comparative study of the density-functional theory concerning the reaction pathway of Si(100)-(2×1) withH2Omolecules

Abstract

Ab initio molecular-orbital calculations were used to examine the reaction pathway of Si(001)-(2×1) with ${\mathrm{H}}_2\mathrm{O}$ molecules. The reliability of the density-functional theory when used to calculate the silicon surface and ${\mathrm{H}}_2\mathrm{O}$ system was carefully examined. I found that the reaction and activation energies along the reaction pathway obtained by the local-density approximation (LDA) differed significantly from those obtained by other methods. This indicates the necessity of treating electron-correlation effects beyond the LDA for this system.