Fig. 7
From: A three-dimensional polyhedral unit model for grain boundary structure in fcc metals
The polyhedral unit model of the Σ3(111) GB is illustrated. a, b The atomistic structure and the dual-tetrahedral units of the twin GB, viewed along the tilt axis \([\bar{1}\,1\,0]\) and along the plane normal [111], respectively, are shown. Due to the translational symmetry of the GB, the unit-cell contains only one dual-tetrahedron, which is highlighted. c The dual-tetrahedron along with the corresponding atoms and the VV-spheres are shown. As discussed in the article, the VV-spheres of the dual-tetrahedron in the twin GB do not overlap
