# 21.3: Join the Crystals to Form the Dislocation

We have determined that the displacements of the atoms are:

$u_{A}(x)=-\frac{b}{2 \pi} \tan ^{-1}\left(\frac{x_{A}}{w}\right)$

$u_{B}(x)=-\frac{b}{2 \pi} \tan ^{-1}\left(\frac{x_{B}}{w}\right)$

From below, the displacements of the atoms on the A-plane are symmetrical on either side of the dislocation line, and are zero at the centre. It is clear that the misfit around the dislocation is of two types: a strain in the planes above and below the dislocation and a misalignment of the atoms across the slip plane.

The process of determining the energies is shown in the following animation: