Role of electronic correlation in the Si(100) reconstruction: A quantum Monte Carlo study - art. no. 016105

Recent low-temperature scanning tunneling experiments have questioned the g enerally accepted picture of buckled silicon dimers as the ground state rec onstruction of the Si(100) surface, undermining the ability of density func tional theory to accurately describe electronic correlations at surfaces. W e present quantum Monte Carlo calculations on large cluster models of the s urface, and conclude that buckling remains energetically favorable even whe n the present-day best treatment of electronic correlation is employed. The implications for experimental interpretation are discussed.