Consideration of lattice translations in computer studies of grain-boundary coincidence

Abstract
The proposal that boundaries between crystals related by a high‐density coincidence misorientation will not contain shared atom sites is examined. The rigid lattice translations which reputedly destroy boundary coincidence in computer‐simulated minimum‐energy grain‐boundary configurations are compared with the set of special displacements which conserve the pattern of coincidence sites. The lattice of all such displacements has been termed the ``DSC lattice''. It is shown that most of the computed translations cited as evidence in support of the proposal are very nearly DSC lattice vectors, and hence shared atoms are still present in the boundaries, in most cases, after the translations. Therefore, little justification for discarding the concept of atom sharing in grain‐boundary structures is provided by the computer calculations performed thus far. The importance of considering the properties of the DSC lattice in computer modeling of coincidence boundaries, both in setting up the computer program and in evaluating its results, is clearly indicated.