Reliability of the structural data for calcite and dolomite extracted from X-ray powder diffraction by Rietveld refinement

In this study, diffraction data of calcite and dolomite were collected using a conventional Bragg-Brentano diffractometer, which is a convenient, low-cost, and highly popular in-house instrument, and their crystal structures were refined by the Rietveld method. The effects of different refinement models on the structural data for calcite and dolomite are discussed and assessed in detail by comparing the data with those in literature. Different refinement models affect bond lengths and atomic coordinates of calcite and dolomite, whereas cell parameters are nearly unchanged. The results indicate the feasibility of extracting structural data of good quality from a conventional Bragg-Brentano diffractometer when appropriate strategies are applied.