A detailed study was made of the structural and vibrational properties of the reconstructed (511) surface. The equilibrium configuration of the surface was determined by using the glue many-body potential, plus molecular dynamics-based annealing and quenching techniques. The (511) surface was found to exhibit a displacive reconstruction, with a quasi-triangular arrangement that was similar to the reconstruction which was found on (100). The vibrational dynamics of the relaxed and reconstructed (511) surface were studied by using the real-space Green’s function method. This permitted a local analysis to be made of the vibrational modes. It revealed a pair of edge-localized modes which were outside of the main band, and a gap mode that was associated with the ridge chains of the (100)-oriented terrace. The low-frequency modes were found to have shifted, as a whole, towards lower frequencies (as compared with the bulk).

A.Kara, C.S.Jayanthi, S.Y.Wu, F.Ercolessi: Physical Review B, 1995, 51[23], 17046-62