Structure of Si(1Â 1Â 4) determined by global optimization methods

In this article we report the results of global structural optimization of the Si(1 1 4) surface, which is a stable high-index orientation of silicon. We use two independent procedures recently developed for the determination of surface reconstructions, the parallel-tempering Monte Carlo method and the genetic algorithm. These procedures, coupled with the use of a highly optimized interatomic potential for silicon, lead to finding a set of possible models for Si(1 1 4), whose energies are recalculated with ab initio density functional methods. The most stable structure obtained here without experimental input coincides with the structure determined from scanning tunneling microscopy experiments and density functional calculations by S.C. Erwin, A.A. Baski, L.J. Whitman [Phys. Rev. Lett. 77 (1996) 687].