  The Peierls stress for a [111]-screw dislocation in bcc Tantalum is
calculated using an embedded atom potential. More importantly, a method is
presented which allows accurate calculations of the Peierls stress in the
smallest periodic cells. This method can be easily applied to ab initio
calculations, where only the smallest unit cells capable of containing a
dislocation can be conviently used. The calculation specifically focuses on the
case where the maximum resolved shear stress is along a {110}-plane.
