WAVEDER
The file WAVEDER contains the derivative of the orbitals with respect to k, more precisely the matrix
[math]\displaystyle{ \langle \phi_{n'k} | \frac{\partial \phi_{nk}}{\partial k_i} \rangle = \frac{1}{\epsilon_{nk} -\epsilon_{n'k}} \langle \phi_{n'k} | \frac{\partial (\mathbf{ H} - \epsilon_{nk} \mathbf{S})}{\partial k_i} | \phi_{nk} \rangle. }[/math]