About the existence of an antiferromagnetic ground state for the (1× 1) structure of Si(111)

A recent proposal by Duke and Ford (Surface Sci. 111 (1981) L685) of strong correlations at the metastable (1× 1) Si(111) surface is shown to be equivalent to our earlier theory of magnetic or charge instabilities at this surface. It is recalled how this can be discussed from a perturbation analysis. Estimates of the Coulomb parameter U are given using recent theoretical results for dangling bond states in silicon. They support the conclusion of an antiferromagnetic 2 × 1 ground state for this surface.