It was recalled that there were 3 reported observations of pseudo-twins in such alloys. It was argued here that pseudo-twinning, using the usual body-centered cubic twinning mode, was impossible if the alloys were fully ordered. The argument was based upon energetic grounds, and used first-principles quantum-mechanical calculations.

A.T.Paxton: Acta Metallurgica et Materialia, 1995, 43[5], 2133-6