Using genetic algorithms for solving heavy-atom sites

A novel procedure has been developed for locating heavy-atom positions in crystals of macromolecules. This method used genetic algorithms (GA's) to search for heavy-atom sites that are consistent with an observed difference Patterson function. The procedure is straightforward to apply, space-group independent, and particularly powerful for cases involving non-crystallographic symmetry of multiple heavy atoms in the asymmetric unit. In this paper, we introduce how GA's are used for determining the heavy-atom positions and show how this method is more efficient than a sequential search.