Epitaxial interfaces between crystallographically mismatched materials
  We report an unexpected mechanism by which an epitaxial interface can form between materials having strongly mismatched lattice constants. A simple model is proposed in which one material tilts out of the interface plane to create a coincidence-site lattice that balances two competing geometrical criteria---low residual strain and short coincidence-lattice period. We apply this model, along with complementary first-principles total-energy calculations, to the interface formed by molecular-beam epitaxy of cubic Fe on hexagonal GaN and find excellent agreement between theory and experiment. 
Steven C. Erwin, Cunxu Gao, Claudia Roder, Jonas L\"ahnemann, Oliver   Brandt
cond-mat.mtrl-sci