Pseudomerohedrally twinned crystal structure of 2,3-diphenylbuta-1,3-diene.

The title compound, C 16 H 14 , is twinned by reticular pseudomerohedry of twin index 2. The primitive monoclinic cell of the single crystal can be transformed into a B-centred pseudo-orthorhombic supercell with a fourfold volume. The twofold twin operation about the reciprocal a* axis of the primitive monoclinic cell is co-directional with the approximate C 2 axis of the molecule and a symmetry element of the orthorhombic supercell. A tentative twin domain model is proposed.