How to generate and view a powder diffraction profile

.. such a reflection list can be easily transformed into a diffraction pattern by convolution with the resolution function of a neutron diffractometer.

• Simple resolution functions can be easily generated with the help of the programs gauss and lorentz. Any other numerical resolution function, e.g. from a measurement or simulation can be used.
• Use program convolute for doing the convolution. Here is an example command: convolute 6 8 results/mcdiff.out 1 2 resultshb/resolution.dat ... this gives magnetic pattern such as shown in fig. 11
• Usually the convolution needs to be done to compare to experimental data and needs only to be evaluated at the experimental data points, for example the measured scattering angle values $2\Theta$. This can be done by adding a data file to the command, convolute 6 8 results/mcdiff.out 1 2 resultshb/resolution.dat 1 2 datafile.dat. In our example the data file contains the experimental data in columns 1 (angle) and columns 2 (Intensity).
• If needed the resolution function can be stretched using stretching values given in a separate column of the data file - the command is then convolute 6 8 results/mcdiff.out 1 2 resultshb/resolution.dat 1 2 datafile.dat 13 (in this example the stretching factor is taken from column 13 of the datafile.
• Generating of the stretching factor: the stretching factor may be generated by program uvw2fwhm from the scattering angle values and the parameters U,V and W (as in FullProf.

Figure 11: Calculated magnetic neutron powder diffraction pattern of NdCu$_2$ [24] at T=2 K. [plot created by program mcdiff+convolute+display]