Structural, electronic, and vibrational properties of Si(111)-2 x 1 from ab initio molecular dynamics.

Abstract

Our findings for the equilibrium structure confirm the Pandey (2 × 1) chain model and are in very good agreement with both LEED and medium-energy ion-scattering data, showing in particular a large buckling of the surface chains. We describe the dynamical path followed during the reconstruction from the ideal bulk-terminated surface, which is found to be unstable. The phonon spectrum, which is calculated ab initio for the first time, shows well-defined surface modes at frequencies close to the measured values