Dear Rietvelders, We are trying to refine the structure of InFeO3(ZnO) compound using GSAS. The compound crystallises in R-3m space group and Zn and Fe occupy the same position (00 0.2171). This result is obtained from single crystal studies of isostructural Ga analogue. When we try to refine PXRD of Fe analogue using these parameters, slight deviations (more than esd) in Fe and Zn positions are seen (Zn: 0.2190(1) and Fe: 0.2126 (2)). My queries are:
1. Does this mean that x-rays can really distinguish between Fe and Zn and not Ga and Zn? 2. Is this evidence of any structural ordering in terms of Zn and Fe? Or even a random placement of Zn and Fe is possible with these deviations? 3. If crystallographically it is not possible, is it acceptable to fix one’s position based on the other? thanking you in advance -- Rajesh T Research Fellow Catalysis and Inorganic chemistry division CSIR-National Chemical Laboratory Pune, India
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