Journal Article

PUBDB-2022-04416

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Advances in the Parameter Space Concept towards Picometer Precise Crystal Structure Refinement—A Resolution Study

Zschornak, M. (Corresponding author)Extern* ; Wagner, C. ; Nentwich, M.Extern*DESY* ; Fischer, K. F. ; Vallinayagam, M.

2024
Wiley-Blackwell [S.l.]

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Please use a persistent id in citations: doi:10.3390/cryst14080684  doi:10.3204/PUBDB-2022-04416

Abstract: The Parameter Space Concept (PSC) is an alternative approach to solving and refining (partial) crystal structures from very few pre-chosen X-ray or neutron diffraction amplitudes without the use of Fourier inversion. PSC interprets those amplitudes as piecewise analytic hyper-surfaces, so-called isosurfaces, in the Parameter Space, which is spanned by the spatial coordinates of all atoms of interest. The intersections of all isosurfaces constitute the (possibly degenerate) structure solution. The present feasibility study investigates the La and Sr split position of the potential high-temperature super-conductor La$_{0.5}$Sr$_{1.5}$MnO$_{4}$ $I4/mmm$, with a postulated total displacement between La and Sr of a few pm by theoretical amplitudes of pre-selected $00l$ reflections ($l = 2, 4, \ldots, 20$). The revision of 15-year-old results with state-of-the-art computing equipment enhances the former simplified model by varying the scattering power ratio$f_{\text{La}}/f_{\text{Sr}}$, as exploitable by means of resonant scattering contrast at synchrotron facilities, and irrevocably reveals one of the two originally proposed solutions as being a “blurred” pseudo-solution. Finally, studying the resolution limits of PSC as a function of intensity errors by means of Monte-Carlo simulations shows both that the split can only be resolved for sufficiently low errors and, particularly for the resonant scattering contrast, a theoretical precision down to $\pm 0.19\,$pm can be achieved for this specific structural problem.

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Contributing Institute(s):

1. PETRA-D (FS-PETRA-D)
2. Informationstechnologie (IT)
3. DOOR-User (DOOR ; HAS-User)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)
3. DFG project 442646446 - Parameter Space Concept als Strukturlösungsmethodik für die Einkristalldiffraktometrie (442646446) (442646446)
4. DFG project 409743569 - Kontrollierte Einstellung der Atomstruktur in Funktionsmaterialien durch akustische Wellen und elektrische Felder (409743569) (409743569)
5. EURIZON - European network for developing new horizons for RIs (871072) (871072)

Experiment(s):

1. PETRA Beamline P23 (PETRA III)

Appears in the scientific report 2024

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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