Kaxiras, EfthimiosPandey, K.C.Bar-Yam, YaneerJoannopoulos, John D.2009-05-011986Kaxiras, Efthimios, K. C. Pandey, Yaneer Bar-Yam, and John D. Joannopoulos. Role of chemical potentials in surface reconstruction: A new model and phase transition of GaAs(111)2x2. Physical Review Letters 56, no. 26: 2819-2821.0031-9007http://nrs.harvard.edu/urn-3:HUL.InstRepos:2894634The role of chemical potentials in surface reconstructions is examined and shown to be crucial for binary semiconductor srufaces such as GaAs(111)2×2. We predict that under As-rich conditions a new model, the As triangle, is the lowest-energy geometry, whereas the Ga-vacancy model is appropriate for Ga-rich conditions. A change in the relative chemical potential of Ga and As should produce a phase transition between the two structures.en-US10.1103/PhysRevLett.56.2819