MEM-based structure-refinement system REMEDY and its applications

F. Izumi, S. Kumazawa, T. Ikeda, W. Z. Hu, Ayako Yamamoto, K. Oikawa

Research output: Contribution to journalArticle

78 Citations (Scopus)

Abstract

A Rietveld-analysis program RIETAN was combined with MEED for a maximum-entropy method (MEM) to grow into an integrated software REMEDY. At first, 'observed' structure factors, Fo, estimated after Rietveld analysis are analyzed by the MEM to give electron/nuclear densities biased by a structural model. Then, we evaluate structure factors, Fc(MEM), by the Fourier transform of the densities and fit the whole powder pattern calculated from the Fc(MEM) data to the observed one to refine parameters irrelevant to the structure. Fo data obtained in such a manner are analyzed again by the MEM. MEM analysis and whole-pattern fitting are alternately repeated until R factors in the pattern fitting no longer decrease. REMEDY was utilized to investigate (a) positional disorder of K+ ions interlayered in KxTi2-x/3Lix/3O4, (b) atomic arrangement of K clusters in K-type LTA, and (c) nuclear/electron-density distribution in HgBa2CuO4+δ.

Original languageEnglish
Pages (from-to)59-64
Number of pages6
JournalMaterials Science Forum
Volume378-381
Issue numberI
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

Maximum entropy methods
maximum entropy method
Rietveld analysis
Electronic density of states
R Factors
Powders
density distribution
Fourier transforms
disorders
Ions
computer programs
Electrons
ions

Keywords

  • Electron density
  • Layered compound
  • Maximum-entropy method
  • Nuclear density
  • Superconductor
  • Whole-pattern fitting
  • Zeolite

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Izumi, F., Kumazawa, S., Ikeda, T., Hu, W. Z., Yamamoto, A., & Oikawa, K. (2001). MEM-based structure-refinement system REMEDY and its applications. Materials Science Forum, 378-381(I), 59-64.

MEM-based structure-refinement system REMEDY and its applications. / Izumi, F.; Kumazawa, S.; Ikeda, T.; Hu, W. Z.; Yamamoto, Ayako; Oikawa, K.

In: Materials Science Forum, Vol. 378-381, No. I, 2001, p. 59-64.

Research output: Contribution to journalArticle

Izumi, F, Kumazawa, S, Ikeda, T, Hu, WZ, Yamamoto, A & Oikawa, K 2001, 'MEM-based structure-refinement system REMEDY and its applications', Materials Science Forum, vol. 378-381, no. I, pp. 59-64.
Izumi F, Kumazawa S, Ikeda T, Hu WZ, Yamamoto A, Oikawa K. MEM-based structure-refinement system REMEDY and its applications. Materials Science Forum. 2001;378-381(I):59-64.
Izumi, F. ; Kumazawa, S. ; Ikeda, T. ; Hu, W. Z. ; Yamamoto, Ayako ; Oikawa, K. / MEM-based structure-refinement system REMEDY and its applications. In: Materials Science Forum. 2001 ; Vol. 378-381, No. I. pp. 59-64.
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