USPEX - Evolutionary crystal structure prediction Colin W. Glass, Artem R. Oganov, Nikolaus Hansen We approach the problem of computational crystal structure prediction, implementing an evolutionary algorithm - USPEX (Universal Structure Predictor: Evolutionary Xtallography). Starting from chemical composition we have tested USPEX on numerous systems (with up to 80 atoms in the unit cell) for which the stable structure is known and have observed a success rate of nearly 100%, simultaneously finding large sets of competitive metastable structures. Here focus is on implementation and discussion of our method. Comp. Phys. Comm. 175, pp. 713-720