In a molecular dynamics simulation the Peierls-Nabarro potential felt by a screw dislocation in a primitive cubic lattice was determined by monitoring the potential energy of the dislocated crystal as a function of the position of the dislocation. In the absence of an external stress, the dislocation, if placed off the equilibrium position, moves towards it. In the quasi-static limit the potential energy of the crystal was the Peierls-Nabarro potential experienced by the dislocation. As the defect moves, it converts potential energy into kinetic energy until all atoms vibrate and the dislocation assumed a position that ensures equipartition between the potential and kinetic energy of the lattice. From the movement towards equilibrium the effective mass of the dislocation per lattice parameter a was determined as 0.1 times the atomic mass. It resists movement with a Newtonian friction coefficient B=0.016Gb/ct, where G was the shear modulus and ct the shear wave velocity.

Construction of the Peierls-Nabarro Potential of a Dislocation from Interatomic Potentials. H.Koizumi, H.O.K.Kirchner, T.Suzuki: Philosophical Magazine, 2006, 86[25-26], 3835-46