A Real-Space Genetic Algorithm for Crystal Structure Determination

There has been much interest in using genetic algorithms for determining the ground-state structure of clusters [1] and nanowires [2], and more recently silicon surfaces [3]. We present a real-space encoded genetic algorithm which is suitable not only for surface structure calculations, but also for bulk crystal structure determination. This algorithm makes use of a novel crossover technique in the generation of offspring. The method is also suitable as a polymorph search, and is flexible enough that population members can have different supercells. We will present results from a variety of empirical and {\it ab initio} systems, where all calculations have been performed using the CASTEP [4] code. \\ \ \\ {[}1{]} {D. M. Deaven and K. M. Ho,{\it Phys. Rev. Lett.},{\bf 75} (1995) {288-291}}\\ {[}2{]} {B. Wang {\it et al}, {\it Phys. Rev. Lett.}, {\bf 86} (2001) 2046-2049}\\ {[}3{]} {F. C. Chuang {\it et al}, {\it Surf. Sci.}, {\bf 573} (2004) L375-L381}\\ {[}4{]} {M. D. Segall {\it et al}, {\it J. Phys.: Cond. Matt.}, {\bf 14} (2002) 2717-2743} \\