  Density-functional theory forces, stresses and energies comprise a database
from which the optimal parameters of a spline-based empirical potential
combining Stillinger-Weber and modified embedded-atom forms are determined.
Accuracy of the potential is demonstrated by predictions of ideal shear,
stacking fault, vacancy migration, elastic constants and phonons all between 0
and 100 GPa. Consistency with existing models and experiments is demonstrated
by application to screw dislocation core structure and deformation twinning in
a tungsten nanorod. Lastly, the potential is used to study the high-pressure
bcc to fcc phase transition.
