External module function dL1 - used by mcdisp

In order to visualize angular momentum fluctuations and to calculate neutron intensities in dipole approximation the external single ion module has to provide the transition matrix elements of the angular momentum by the vector $L1$, which is given by: ${\rm L1}^s_{\alpha}=\sqrt{(p_--p_+)}\langle -\vert\hat L^s_{\alpha}-\langle\hat L^s_{\alpha}\rangle_{\mathbf H,T}\vert+\rangle$.

The format to be used is:

extern "C" int dL1(int & tn,double & T,Vector & Hxc,Vector & Hext,double * g_J,Vector & MODPAR,
char ** sipffilename,ComplexVector & L1,float & maxE, ComplexMatrix & est)

The meaning of the symbols follows exactly that of function dm1 and therefore not explained here.