Аннотация:Several qualitatively different structural models have been examined in a critical evaluation of spectroscopic and other data for the Si(111)-(2\ifmmode\times\else\texttimes\fi{}1) surface. Within the one-electron theory, only a novel $\ensuremath{\pi}$-bonded chain model with a covalent surface, and not the generally accepted buckled model with an ionic surface, is consistent with the data.
