The Rietveld method of structure refinement with powder diffraction patterns was originally devised for the analysis of fixed-wavelength (angle-dispersive) neuron data [1] [2] but now constitutes a major breakthrough for the usefulness of X-ray powder data [3]. This powerful method has greatly extended the amount of structural detail which can be obtained routinely from powder diffraction patte...

A complex refinement of the structure of the battery cathode material, Li1.2Mn0.4Ni0.3Co0.1O2, using neutron and resonant diffraction data is used to demonstrate SVDdiagnostic as a useful tool to diagnose problems in the least squares normal matrix. SVDdiagnostic examines both the unprocessed and pre-conditioned matrices and outputs a 'condition' number as well as combinations of variables caus...

The quality of X-ray powder diffraction data and the number type refinable parameters have been examined with respect to their effect on quantitative phase analysis (QPA) by Rietveld method using collected from two samples QPA round robin [Madsen et al. J. Appl. Cryst. (2001), 34, 409-26]. From these analyses best-case-scenario specimens, a series recommendations for minimum standards collectio...

Sodium dicyanamide NaC2N3 was found to undergo two phase transitions. According to thermal analysis and temperature-dependent X-ray powder diffractometry, the transition of alpha-NaC2N3 (1a) to beta-NaC2N3 (1b) occurs at 33 degrees C and is displacive. 1a crystallizes in the monoclinic system, space group P21/n (no. 14), with a = 647.7(1), b = 1494.8(3), c = 357.25(7) pm, beta = 93.496(1) degre...