Leandro Bravo said: > I don´t think that the kaolinite CIF that I´m using is working well, I´m > refining the temperature factors and it´s giving me non realistic numbers. > Can somebody send me a trustable kaolinite CIF, with good temperature > factors?!
You will find a dozen papers on the structure of kaolinite in ICSD. You should be able to download for free the ones in Clays and Clay Minerals by constructing URLs like this: http://www.crossref.org/openurl?aulast=Neder&title=Clays%20and%20Clay%20Minerals&volume=47&spage=487&year=1999 > Other doubt... I´m making my scans from 5 (2-theta) to 120 (2-theta), and > I´m realizing that above 80° I´m getting unecessary data (basically just > backgorund). The question is how this ´´unecessary data`` affect the > quantification?!?! I guess you may well have trouble refining realistic temperature factors if you are also refining the background and you can see no peaks above 80°. Clays are often not well ordered. You can't blame TOPAS or the CIF for that :-) Try fixing the background and/or temperature factors. Neder, R.B.;Burghammer, M.;Grasl, T.;Schulz, H.;Bram, A.;Fiedler, S. Refinement of the kaolinite structure from single-crystal synchrotron data (1999) Clays and Clay Minerals 47, 487-494 Akiba, E.; Hayakawa, H.; Hayashi, S.; Miyawaki, R.; Tomura, S.; Shibasaki, Y.; Izumi, F.; Asano, H.; Kamiyama, T. Structure refinement of synthetic deuterated kaolinite by Rietveld analysis using time-of-flight neutron powder diffraction data (1997) Clays and Clay Minerals 45, 781-788 Bish, D.L. Rietveld refinement of the kaolinite structure at 1.5K (1993) Clays and Clay Minerals 41, 738-744 Bish, D.L.;von Dreele, R.B. Rietveld refinement of non-hydrogen atomic positions in kaolinite (1989) Clays and Clay Minerals 37, 289-296 Young, R.A.;Hewat, A.W. Verification of the Triclinic Crystal Structure of Kaolinite (1988) Clays and Clay Minerals 36, 225-232 _____________________________________________________________ Dr Alan Hewat, ILL Grenoble, FRANCE <[EMAIL PROTECTED]>fax+33.476.20.76.48 +33.476.20.72.13 (.26 Mme Guillermet) http://www.ill.fr/dif/people/hewat/ _____________________________________________________________
