Methylthiolate induced vacancy formation on Au(111): a density functional theoretical study

We have studied various possible molecular configurations of methylthiolate (MeS) adsorbed Au(111)c(4root3 x 2root3) 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 root3- x root3 structure, being inconsistent with experimental observations. From our GGA calculations, we point out a possibility of vacancy formation in the first An layer of MeS adsorbed Au(111) surfaces. (C) 2002 Elsevier Science B.V. All rights reserved.