Using density functional theory, it was found that high pressures intrinsically favoured twinning in niobium by reducing the thickness of a stable twin. Five empirical interatomic potentials for niobium were considered in molecular dynamics shock simulations. The results showed that two potentials exhibited the experimentally observed twinning behaviour. Comparing with density functional theory under high pressure, it was found that these two potentials were capable of reproducing the generalized stacking fault curve, but the others predicted several artificial metastable states along the generalized stacking fault curve resulting in an artificial structural transformation.

Twinning in BCC Metals under Shock Loading: a Challenge to Empirical Potentials. R.F.Zhang, J.Wang, I.J.Beyerlein, T.C.Germann: Philosophical Magazine Letters, 2011, 91[12], 731-40