External module function pcalc - used by mcdiff and mcphas

In order to calculate the position $\langle \hat \mathbf P\rangle$ the following function has to be present in the module file *.so:

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

It returns the position vector P of an Einstein oscillator in units of Å under the action of a Force Fxc in units of meV. For the rest it works exactly as mcalc, therefore we do not give more details here.