Computer modelling was applied to the atomic structures of symmetrical tilted grain boundaries with a [110] misorientation axis, and  = 9. Various states of rigid relative translation of the lattices of adjacent grains were considered. Degenerate metastable boundary configurations were found. These could be represented as a collection of Bernal polyhedra-tetrahedra and pentagonal bi-pyramids which were oriented along the misorientation axis. It was found that the components of the rigid displacement of the lattices of multiple boundary structures were related to the basis vectors of the grain-boundary displacement lattice.

T.I.Mazilova, I.M.Mikhailovskii: Fizika Tverdogo Tela, 1995, 37[1], 212-6 (Physics of the Solid State, 1995, 37[1], 113-5)