The injection (creation) process of a straight screw dislocation is compared atomistically with elastodynamic continuum theory. A
method for injecting quiescent screw dislocations into a crystal of tungsten is simulated using non-equilibrium molecular dynamics.
The resulting stress fields are compared to the those of elastodynamic solutions for the injection of a quiescent screw dislocation.
A number of differences are found: a plane wave emission is observed to emanate from the whole surface of the cut used to create
the dislocation, affecting the displacement field along the dislocation line (z), and introducing displacement field components
perpendicular to the line (along x and y). It is argued that, in part, this emission is the result of the finite time required to inject
the dislocation, whereby the atoms in the cut surface must temporarily be displaced to unstable positions in order to produce the
required slip. By modelling this process in the continuum it is shown that the displacements components normal to the dislocation
line arise from transient displacements of atoms in the cut surface parallel to x and y. It is shown that once these displacements are
included in the elastodynamic continuum formulation the plane wave emission in uz
is correctly captured. A detailed comparison
between the atomistic and continuum models is then offered, showing that the main atomistic features can also be captured in the
continuum.