  While computational methods for the study of point defects in materials have
received significant attention, methods for the investigation of grain
boundaries require further development. In this study, we applied a genetic
algorithm to find the atomic structure of grain boundaries in semiconductor
materials with given Miller indices and investigated their electronic
structure. Our study of the {\Sigma}3 (112) grain boundary in CdTe shows that
the stability of grain boundaries can be greatly enhanced by breaking mirror
symmetry, locally or globally. The resulting grain boundary can be electrically
less harmful because the origin of the defect levels are removed from the
middle of the band gap and the grain boundaries can serve as a channel for
electron extraction.
