title: Density functional theory simulation of the adsorption of sulphur multilayers on Au(100).
abstract: The adsorption of sulphur multilayers on Au(100) has been studied using density functional theory (DFT) within the generalized gradient approximation (GGA). The first sulphur layer was adsorbed on the four-fold sites of the unreconstructed Au(100) surface forming a lattice. The experimental parameters of the lattice were reproduced taking into account the surface expansion of the topmost Au(100) layer. This expansion should occur when gold islands are formed after the lifting of hex-reconstruction, which allows the lateral movement of the gold atoms. The second sulphur layer, on top of the lattice, consisted of eight S atoms (octomer phase) in a quasi-rectangular arrangement. The structural optimization of the octomer phase was achieved in a specific spatial orientation with respect to the lattice. The analysis of Bader atomic charges and the projected density of states (PDOS) demonstrated that charge transfer from the Au(100) surface to the sulphur layers, sulphur chemisorption and sulphur-sulphur inter-layer mixing of electronic states control the formation of sulphur multilayers.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Hernandez-Tamargo
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba. mayrap@fisica.uh.cu.
authors.forename: Ransel
authors.initials: R
authors.lastname: Barzaga
authors.affiliation: Invited Professor, Facultad de Física, Universidad de La Habana, San Lázaro y L, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba.
authors.forename: Hans
authors.initials: H
authors.lastname: Mikosch
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba. mayrap@fisica.uh.cu.
authors.forename: Javier A
authors.initials: JA
authors.lastname: Martínez
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba. mayrap@fisica.uh.cu.
authors.forename: José A
authors.initials: JA
authors.lastname: Herrera
authors.affiliation: Universidad Nacional Autónoma de México (UNAM), Centro de Nanociencias y Nanotecnología (CNyN), Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, Mexico.
authors.forename: M H
authors.initials: MH
authors.lastname: Farías
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba. mayrap@fisica.uh.cu and Invited Professor at CNyN, UNAM, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, Mexico.
authors.forename: Mayra P
authors.initials: MP
authors.lastname: Hernández