Although systematic absences and symmetry relations among reflections pointed to space group I4122 (one mol. in the asym. unit), a direct methods soln. could only be obtained in I.hivin.4 (two mols. in the asym. unit). Refinement in I.hivin.4 was unsatisfactory until merohedral twinning was taken into account. The resulting mol. dimensions are in excellent agreement with analogous values in the literature. The mol. arrangement is described.