Kaxiras, EfthimiosBar-Yam, YaneerJoannopoulos, John D.Pandey, K.C.2013-05-011987Kaxiras, Efthimios, Yaneer Bar-Yam, John D. Joannopoulos, and K.C. Pandey. 1987. Ab initio theory of polar semiconductor surfaces. I. Methodology and the (22) reconstructions of GaAs(111). Physical Review Series B 35, no. 18: 9625-9635.1098-0121http://nrs.harvard.edu/urn-3:HUL.InstRepos:10605457A methodology is developed for the theoretical study of the polar surfaces of compound semiconductors. It is based on the calculation of the total energy in the context of density-functional theory in the pseudopotential approximation. The method is used to investigate the (2×2) reconstructions of GaAs(111). Emphasis is given to the relative chemical potential, which plays a crucial role in determining the lowest-energy geometry for surfaces with different stoichiometries. The total-energy versus chemical-potential curves indicate that there are at least two stable reconstructions. We predict one to be an As-triangle geometry and the other the Ga vacancy.en-USJournal Article2013-05-0110.1103/PhysRevB.35.9625