The generalized coincidence-site network model was used to study face-centered cubic twist [100] grain boundaries. This led to a detailed atomistic description of general twist grain boundaries. According to the model, singular boundaries - which were defined as being those which contained only 1 primary dislocation per coincidence-site lattice unit cell - were suggested to be composed of atomic domains with an S1 structure, separated by an array of perfect primary dislocations. Every random boundary had an associated singular boundary, and its structure consisted of a mixture of domains which were found in the associated boundary in various translational states. These domains were separated by an array of partial secondary dislocations. A non-singular boundary therefore contained arrays of both primary and secondary dislocations.

Detailed Atomic Structure of Arbitrary FCC [100] Twist Grain Boundaries. D.Romeu, L.Beltran-del-Rio, J.L.Aragon, A.Gomez: Physical Review B, 1999, 59[7], 5134-41