title: Atomic structure of the GaAs(001)-c(4x4) surface: first-principles evidence for diversity of heterodimer motifs.
abstract: The GaAs(001)-c(4x4) surface was studied using ab initio atomistic thermodynamics based on density-functional theory calculations. We demonstrate that in a range of stoichiometries, between those of the conventional three As-dimer and the new three Ga-As-dimer models, there exists a diversity of atomic structures featuring Ga-As heterodimers. These results fully explain the experimental scanning tunneling microscopy images and are likely to be relevant also to the c(4x4)-reconstructed (001) surfaces of other III-V semiconductors.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin-Dahlem, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Penev
authors.forename: P
authors.initials: P
authors.lastname: Kratzer
authors.forename: M
authors.initials: M
authors.lastname: Scheffler