  We show here how density functional theory calculations can be used to
predict the temperatureand orientation-dependence of the yield stress of
body-centered cubic (BCC) metals in the thermallyactivated regime where
plasticity is governed by the glide of screw dislocations with a 1/2 <111>
Burgers vector. Our numerical model incorporates non-Schmid effects, both the
twinning/antitwinning asymmetry and non-glide effects, characterized through ab
initio calculations on straight dislocations. The model uses the
stress-dependence of the kink-pair nucleation enthalpy predicted by a line
tension model also fully parameterized on ab initio calculations. The
methodology is illustrated here on BCC tungsten but is applicable to all BCC
metals. Comparison with experimental data allows to highlight both the
successes and remaining limitations of our modeling approach.
