The 1 2 screw dislocations in bcc iron are studied by atomistic simulations. An analytical
yield criterion captures correctly the non-Schmid plastic behavior. A model Peierls potential
develops a link between the atomistic modeling at 0 K and the thermally activated dislocation
motion. All predicted features agree well with experimental observations. This work establishes
a consistent bottom-up model that provides an insight into the microscopic origins of the
plastic behavior of bcc iron.
