The validity of the structure-property relationships governing the low-temperature deformation behavior of many body-centred cubic metals was brought into question with recent ab initio density functional studies of isolated screw dislocations in Mo and Ta. These relationships were semi-classical in nature, having grown out of atomistic investigations of the deformation properties of the group-V and group-VI transition metals. It was found that the correct form for these structure-property relationships was fully quantum mechanical, involving the coupling of electronic states with the strain field at the core of long a/2<111> screw dislocations.

Electronic Selection Rules Controlling Dislocation Glide in BCC Metals. T.E.Jones, M.E.Eberhart, D.P.Clougherty, C.Woodward: Physical Review Letters, 2008, 101[8], 085505