Electronic structures were calculated for two typical reconstruction models of the Si(111)-7 x 7 surface, i.e. the buckled and the vacancy models. The first-principles discrete variational DV-X alpha calculations were carried out for the surface cluster without a vacancy (Si13H15) and with a vacancy (Si12H15). Essential characteristics in the electronic structure were elucidated which were closely related to surface atomic arrangements. The low-density vacancy model proposed by Ino (1980) was pointed out to be a promising reconstruction mode for the Si(111)-7 x 7 surface.

Electronic Structure of Buckled and Vacancy Models of Si(111)-7 x 7 Surface by DV-Xα Cluster Method. K.Nakamura, T.Hoshino, M.Tsukada, S.Ohnishi, S.Sugano: Journal of Physics C, 1981, 14[15], 2165-73