where (x n , y n , z n ) = 2π L (x, y, z) with L being the periodicity of the crystal. We expect the Q I phase to be composed of distorted bilayers, since our collaborators have shown that the Q I consists of annular pores between head groups. Under this assumption, we propose a method to determine the most likely space group by testing how a lamellar bilayer can fit within the mathematical representations of the Q I phase.