Conventional design tools were not developed for designing square zero-shift supercells. Conventionally, solutions that enable square zero-shift supercells were found by trial and error or by exhaustive analysis. According to a first design criterion of this invention, a non-square supercell in a first frame of reference has a diagonal that is equal in length to the diagonal of a square supercell in a second frame of reference rotated at a desired screen angle to the first frame of reference. The screen angle is a function of the lengths of the sides of the non-square supercell in the first frame of reference. According to a second design criterion, if the area of the corresponding square supercell in the second frame of reference is an integer, a square zero-shift supercell can be designed based on the lengths of the sides of the non-square supercell in the first frame of reference.