ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
On every line of a X-ray powder-diagram there is more than one reflection, at least there are hkl and hkl. In the tetragonal, trigonal-hexagonal and cubic crystalsystems, these systematically coinciding reflections generally have different intensities (2 or 4 kinds), except in the highest-symmetry LAUE class.So in structure determination, the conventional reliability quotient R has to be replaced by \documentclass{article}\pagestyle{empty}\begin{document}$$ \tilde R = (\Sigma |\tilde F_{obs}^2 - \tilde F_{cal}^2 |)/\Sigma \tilde F_{obs}^2, $$\end{document} where the \documentclass{article}\pagestyle{empty}\begin{document}$ \tilde F^{2,}s $\end{document}2's are the sums of the 2 or 4 (LP-corrected) intensities coinciding on a line. An IBM-1620 program was written to calculate \documentclass{article}\pagestyle{empty}\begin{document}$ {\tilde R} $\end{document}, starting with the output of ICR-4 structure factor program. An application is given in the immediately following paper by LUDI,GÜDEL and BÜRKI.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19680510621
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