It was recalled that recent low-temperature scanning tunnelling experiments had put in doubt the generally accepted picture of buckled dimers as being the ground-state reconstruction of the Si(100) surface. This then undermined the ability of density functional theory to describe accurately the electronic correlations at surfaces. Quantum Monte Carlo calculations were made of large-cluster models of the surface, and it was concluded that buckling remained energetically favourable; even when the best electronic correlation treatment was used.

Role of Electronic Correlation in the Si(100) Reconstruction: a Quantum Monte Carlo Study. S.B.Healy, C.Filippi, P.Kratzer, E.Penev, M.Scheffler: Physical Review Letters, 2001, 87[1], 016105 (4pp)