It was shown that for dislocations in crystalline solids, except for pure edge and screw dislocations, the local relative displacement of the two sides of the glide plane always deviated from the direction of the Burgers vector of the crystallographic Volterra dislocation.

Deviations from Volterra Dislocations G.Schoeck: Philosophical Magazine Letters, 1998, 77[3], 141-6