A tetrahedron model was proposed for describing the slip planes and Burgers vectors of dislocations in the tetragonal C11h structured material. The faces were made up of the four {013} slip planes, the edges consisted of the four ½<331> Burgers vectors plus the two <300> vectors. Included in the tetrahedron were the two (100), two (110) and four ½<111> Burgers vectors; plus partial dislocations such as 1/6<331>, ¼<111> and 1/3<001>. Various dislocation reactions were described. In particular, it was shown that the ½<331> screw dislocation should dissociate into three 1/6<331> partials in an asymmetrical fashion on two {013} planes. It was expected that such a configuration would have differing mobilities in tension and compression. As an alternative, a pyramid model was described. This had some advantages, but was less compact than the tetrahedron model.

A Dislocation Tetrahedron for MoSi2. T.E.Mitchell: Acta Materialia, 2000, 48[10], 2713-8