Honeycomb chain structure of the Au/Si(111)-(5 x 2) surface reconstruction: A first-principles study

Models with a honeycomb chain feature for the Au/Si(111)-(5x2) surface reconstruction are systematically examined using first-principles calculations. The atomic and electronic structures of these models are analyzed in detail. Our calculation shows that one of these models has a lower surface energy than the previously proposed models by Erwin [Phys. Rev. Lett. 91, 206101 (2003)] and by Riikonen and Sanchez-Portal [Phys. Rev. B 71, 235423 (2005)]. This newly identified model also reproduces certain key features in the angle-resolved photoemission measurement and experimental scanning tunneling microscopy images.