Ab initio investigation of Bi-covered GaSb(110) surfaces

We present theoretical studies for the Bi chemisorbed GaSb(110) surface usi ng ab initio pseudoptential calculations. Our results give strong support t hat the metastable (1 x 1) phase is best described by the epitaxially conti nued layer structure. We also investigate a number of structures for the st able (1 x 2) phase and conclude that the system is best described by the mo dified epitaxially continued layer structure mechanism reported by van Gemm eren et nl. The calculated electronic structure is found to be in excellent agreement for both phases with angle-resolved ultraviolet photoemission sp ectroscopy data presented by McIlroy et-al., whereas geometric parameters a gree excellently with those obtained by van Gemmeren et al.