IUCr journals

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

Acta Cryst. (2005). C61, o300–o302

[Twinned structure] Orientation of the molecule in the monoclinic crystal lattice and its relation to the B-centered pseudo-orthorhombic twin lattice.
This article describes the structure determination of the small organic molecule C16H14 and a proposed nano-scale twinning model. The monoclinic crystal lattice is twinned by reticular pseudomerohedry (index 2) to form a B-centered orthorhombic supercell (twincell) with β = 90.6°. The approximate molecular twofold axis coincides with the twin axis and a lattice direction of the supercell. This paper illustrates that currently available twin-detection software (Dirax, Rotax, PLATONTwinRotMat), twin-integration software (EvalCCD) and twin-refinement software (SHELXL) can make a previously involved problem routine.

M. Lutz, A. L. Spek, B. C. van der Wiel and C. A. van Walree