Bragg R factor
From Online Dictionary of Crystallography
Bragg-R-Wert (Ge). Factor R de Bragg (Sp).
Definition
The R factor measuring the agreement between the reflection intensities calculated from a crystallographic model and those measured experimentally.
[math]R_B = {{\sum | I_{obs} - I_{calc} | } \over {\sum |I_{obs} |}}[/math].
In the Rietveld method RB is useful because it depends on the fit of the structural parameters and not on the profile parameters.