Atomic and Electronic Structure of the 7 × 7 Reconstructed Si (111) Surface

It is suggested that the 2×{}1 and 7×{}7 reconstructions of Si(111) surfaces are inherently quite similar and propose a 7×{}7 structure based on ringlike arrangements of positively and negatively charged surface atoms. High-resolution angle-resolved photoemission data are shown to provide strong support for the buckled, (2×{}1)-like nature of the 7×{}7 surface.