Typical values of Rietveld instrument profile coefficients

GSAS instrument parameters are tabulated for a variety of laboratory and synchrotron diffractometers to give users an idea of the typical ranges of profile parameters when they generate their own instrument parameter files. For modern high-resolution laboratory diffractometers, the parameters fall in the ranges 0<U<3, V=0, 0<W<4. 1<X<3. 0<Y<3, 1<asym<3, and 0<S/L <0.03. For synchrotron diffractometers, the parameters fall in the ranges 0<U<1.2, -1<V<0. 0<W<1, 0 <X<1, 0 <Y<1, 0<asym<0.5. 0<S/L<0.001. and 0<H/L<0.007. FULLPROF equivalents are also reported. The factors which are convoluted together to generate the instrument profile are described. (C) 2011 International Centre for Diffraction Data. [DOI: 10.1154/1.3548128]