The problem of the relative energetic stabilities of high-order reconstructions of the Ge(001) surface was revisited with more refined first-principles calculations. Deducing the parameters of the Ising model from this result, Monte Carlo simulations were made of the phase transition of the asymmetrical dimer directions. The Monte Carlo simulation reproduces fairly well the experimental transition temperature of an X-ray-diffraction experiment. The potential-energy curve of the dimer flip-flop motion in the p(2 x 1) structure was determined. The obtained geometry of the c(4 x 2) structure also agrees fairly well with the results of an X-ray diffraction experiment.

Ge(001) Surface Reconstruction Studied using a First-Principles Calculation and a Monte Carlo Simulation. Y.Yoshimoto, Y.Nakamura, H.Kawai, M.Tsukada, M.Nakayama: Physical Review B, 2000, 61, 1965-70