 This hexagonal phase is often referred to as a (28×5) structure, distorted and rotated by about 0.81° relative to the [011] crystal direction.Molecular dynamics simulations indicate that this rotation occurs to partly relieve a compressive strain developed in the formation of this hexagonal reconstruction, which is nevertheless favored thermodynamically over the unreconstructed structure.However, this rotation disappears in a phase transition at approximately "T" = 970 K, above which an un-rotated hexagonal structure is observed.