The core structures of <111> screw dislocations in body-centered cubic metals were studied by using density functional theory and the local-density approximation. For Mo, direct calculation of the core structure showed the core to be symmetrical with respect to 180° rotations around an axis perpendicular to the dislocation line. Use of the Vitek-Duesbery criterion suggested the existence of symmetrical core structures for all of the studied metals.

Density Functional Theory Studies of Screw Dislocation Core Structures in BCC Metals. S.L.Frederiksen, K.W.Jacobsen: Philosophical Magazine, 2003, 83[3], 365-75