Environment-dependent bond-order potentials were developed for L10 TiAl, body-centered cubic Mo and face-centered cubic Ir. They comprise both the angular character of bonding and the screening effect of nearly free electrons. These potentials were used in atomistic studies of screw dislocations that revealed the non-planar character of their cores. It was argued that both the covalent as well as the metallic characteristics of the bonding governed these structures, which then controlled the mechanical behaviour.

Dislocations in Materials with Mixed Covalent and Metallic Bonding. D.Nguyen-Manh, M.J.Cawkwell, R.Gröger, M.Mrovec, R.Porizek, D.G.Pettifor, V.Vitek: Materials Science and Engineering A, 2005, 400-401, 68-71