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Validation of missed space‐group symmetry in X‐ray powder diffraction structures with dispersion‐corrected density functional theory
Author(s) -
Hempler Daniela,
Schmidt Martin U.,
van de Streek Jacco
Publication year - 2017
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520617005935
Subject(s) - density functional theory , group (periodic table) , space (punctuation) , space group , symmetry (geometry) , crystal (programming language) , group theory , symmetry group , energy minimization , crystal structure , diffraction , dispersion (optics) , physics , mathematics , crystallography , geometry , quantum mechanics , x ray crystallography , chemistry , computer science , programming language , operating system
More than 600 molecular crystal structures with correct, incorrect and uncertain space‐group symmetry were energy‐minimized with dispersion‐corrected density functional theory (DFT‐D, PBE‐D3). For the purpose of determining the correct space‐group symmetry the required tolerance on the atomic coordinates of all non‐H atoms is established to be 0.2 Å. For 98.5% of 200 molecular crystal structures published with missed symmetry, the correct space group is identified; there are no false positives. Very small, very symmetrical molecules can end up in artificially high space groups upon energy minimization, although this is easily detected through visual inspection. If the space group of a crystal structure determined from powder diffraction data is ambiguous, energy minimization with DFT‐D provides a fast and reliable method to select the correct space group.