External module function pelcalc - used by mcdiff and mcphas

In order to calculate the electric dipole moment $\langle \hat \mathbf p_{el} \rangle$ the following function has to be present in the module file *.so:

extern "C" void pelcalc(Vector & P,double * T, Vector & Fxc, Vector & Hext,
                      double * gJ, Vector & MODPAR,
                      char ** sipffilename, ComplexMatrix & Icalc_parstorage);

It returns the electric dipole moment vector pel in units of $\vert e\vert$pm under the action of a Force Fxc in units of meV, and external field (electric field as components 4,5,6 of Hext in units of kV/mm). For the rest it works exactly as mcalc, therefore we do not give more details here.