X-Ray Diffraction and Symmetry

Rowan computes space groups and X-ray diffraction (XRD) peaks from periodic crystal structures.

The space group is determined from the symmetry operations of the crystal and reported as both the international symbol and the space group number.

Peak intensities are computed from structure factors using Cromer–Mann atomic form factors, then normalized so the strongest peak has intensity 100. Lorentz–polarization factors are applied automatically.


Wavelengths

Four standard X-ray sources are available:

SourceWavelength (Ã…)Notes
Cu Kα1.5406Standard laboratory source
Mo Kα0.7107Shorter wavelength; good for small molecules and single-crystal work
Co Kα1.7890Common for iron-containing samples
Ag Kα0.5608Very short; suited to high-pressure or high-angle measurements
X-Ray Diffraction and Symmetry | Rowan Documentation