Methylthiolate induced vacancy formation on Au(1 1 1): a density functional theoretical study

We have studied various possible molecular configurations of methylthiolate (MeS) adsorbed Au(1 1 1)c(43×23) surfaces using density functional theory within a generalized gradient approximation (GGA). Assuming unreconstructed substrate, four-chain models which have four crystallographically distinct molecules in a unit cell are less stable than a one-chain model, that is, a simple 3×3 structure, being inconsistent with experimental observations. From our GGA calculations, we point out a possibility of vacancy formation in the first Au layer of MeS adsorbed Au(1 1 1) surfaces.