Efficient fitting of single-crystal diffuse scattering in interaction space: a mean-field approach

Autor: Ella M. Schmidt, Johnathan M. Bulled, Andrew L. Goodwin
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: IUCrJ, Vol 9, Iss 1, Pp 21-30 (2022)
Druh dokumentu: article
ISSN: 2052-2525
20522525
DOI: 10.1107/S2052252521009982
Popis: The diffraction patterns of crystalline materials with strongly correlated disorder are characterized by the presence of structured diffuse scattering. Conventional analysis approaches generally seek to interpret this scattering either atomistically or in terms of pairwise (Warren–Cowley) correlation parameters. Here it is demonstrated how a mean-field methodology allows efficient fitting of diffuse scattering directly in terms of a microscopic interaction model. In this way the approach gives as its output the underlying physics responsible for correlated disorder. Moreover, the use of a very small number of parameters during fitting renders the approach surprisingly robust to data incompleteness, a particular advantage when seeking to interpret single-crystal diffuse scattering measured in complex sample environments. As the basis of this proof-of-concept study, a toy model is used based on strongly correlated disorder in diammine mercury(II) halides.
Databáze: Directory of Open Access Journals