TY - JOUR
T1 - MEM-based structure-refinement system REMEDY and its applications
AU - Izumi, F.
AU - Kumazawa, S.
AU - Ikeda, T.
AU - Hu, W. Z.
AU - Yamamoto, A.
AU - Oikawa, K.
PY - 2001/1/1
Y1 - 2001/1/1
N2 - 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.
AB - 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.
KW - Electron density
KW - Layered compound
KW - Maximum-entropy method
KW - Nuclear density
KW - Superconductor
KW - Whole-pattern fitting
KW - Zeolite
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U2 - 10.4028/www.scientific.net/msf.378-381.59
DO - 10.4028/www.scientific.net/msf.378-381.59
M3 - Conference article
AN - SCOPUS:4243573479
SN - 0255-5476
VL - 378-381
SP - 59
EP - 64
JO - Materials Science Forum
JF - Materials Science Forum
IS - I
T2 - 7th European Powder Diffraction Conference
Y2 - 20 May 2000 through 23 May 2000
ER -