By treating the twinning process as a simple homogeneous shear, the twin elements and twin systems in this material were classified. It was established that there were 2 systems of conjugated twins in orthorhombic crystals. The first one was a degenerate system with a {110} twinning plane, and the second system comprised twins with {224} twinning planes and axial twins with a <111> rotation axis.

D.I.Savitskii, S.B.Ubizskii, L.O.Vasilechko, A.O.Matkovskii: Kristallografiya, 1996, 41[5], 902-6 (Crystallography Reports, 1996, 41[5], 859-63)