NaCl powder diffraction data collected in a 0.2 mm capillary on
a Stoe Stadi-P diffractometer.
You should notice that the reflections with hkl even are much stronger
than those with hkl odd: for hkl even, the scattering factors
of Na and Cl are additive, while for hkl odd they are opposed.
The sample was also measured in flat-plate mode in Bragg-Brentano geometry.
In this mode preferred orientation results in an enhanced intensity for the 200
reflection, adversely affecting the ratio of intensities of the 111
and 200 reflections.