Assessment of interatomic potentials for 1/2 < 111 > screw dislocation properties in tungsten and molybdenum

In this work, we systematically evaluated 27 W and 19 Mo interatomic potentials focusing on bulk and screw dislocation properties. The bulk properties primarily include: elastic constants, bulk modulus, shear modulus, Poisson’s ratio, and stacking fault energy; and the screw dislocation properties mainly consist of: differential displacement map of core structure, Peierls energy barrier, and Peierls stress. We identified six W potentials and three Mo potentials that are suitable for screw dislocation simulations. The computational efficiency of these selected potentials was subsequently benchmarked. Finally, considering both accuracy and computational efficiency, we employed three representative interatomic potentials to investigate the effect of temperature on screw dislocation motion. The critical resolved shear stress for dislocation motion decreases with increasing temperature and is accompanied by enhanced cross-slip propensity. This work offers a reference for selecting appropriate interatomic potentials in molecular dynamics simulations to investigate screw dislocation properties in W and Mo.