The program *McDisp* may be used straightforward to calculate quasi elastic intensity
by

- specification of an energy
range [emin,emax] in file
*mcdisp.par*which corresponds to the interval of energies (around zero energy transfer) sensed by the detector of the diffuse scattering experiment. - quasi elastic intensity is expected only in the paramagnetic state - thus in
*mcdisp.mf*a a temperature above the magnetic ordering temperature should be selected. - start
*mcdisp*in the usual way, using the DMD method.

The file *mcdisp.dsigma.tot* produced by the calculation contains the calculated diffuse scattering cross section.
Figure 12 shows an output of such a calculation for the diffuse scattering
on HoTiO.

For comparison it is also possible to do a calculation using the option *-r* forcing
the program *mcdisp* to calculate the cross section
using the full MF-RPA algorithm (output stored in *mcdisp.dsigma*)

Martin Rotter 2017-01-10