The structure of the (001) surface was investigated by combining first-principles total-energy calculations with soft X-ray photo-electron spectroscopy and scanning tunnelling microscopy. The 4 x 2 cation dimer reconstruction, and the more complex 2 x 4 trimer reconstruction, were found to be unstable. The energetically favoured 2 x 4 reconstruction was stabilized by dimerized In and P atoms. Unlike the case of the GaAs surface, however, mixed In-P dimers were preferred for cation-rich surfaces; due to the appreciable size difference between the constituents.

W.G.Schmidt, F.Bechstedt, N.Esser, M.Pristovsek, C.Schultz, W.Richter: Physical Review B, 1998, 57[23], 14596-9