>For Armel, here are a couple of examples of automatic indexing, search-match >and structure DETERMINATION from neutron powder data.
OK, let us make a 2018 analysis of Pawley & Hewat (1985) Acta Ctyst. B41, 136-130. according to 2002 criteria sample : CF3Cl = strong chemical information Neutron : D1A (ILL) lamda = 2.98 A Indexing : Visser (1969) : orthorhombic cell C-centered from systematic absences estimation of 4 molecules per cell A packing-analysis program written to investigate CF3Cl in Cmc21 two variables needed : translation of the molecule along y and rotation in the yz plane Unit cell refined using the ALLHKL (Pawley, 1981) program Final full refinement by EDINP (Pawley, 1980) All this fits well into the SDPD 2002 maze http://www.cristal.org/CAC-XX/Hewat-maze.jpg You had Pawley with you... His packing-analysis software can be considered as a precursor of what is called nowadays the direct-space approach, rotating and translating a known molecule (using a grid-search approach I presume in that case) till obtaining a good fit. A pity that he has not solved his 1981 example for his Pawley method (decafluorocyclohex-1-ene, C6F10) using that software (was a bit more complex). So, this 1985 SDPD paper cannot be considered as a good example for a confirmation of the "structure determined by the Rietveld method" approach. but sure it is a nice structure DETERMINATION from neutron powder data. Best Armel > Message du 29/08/18 12:33 > De : "Alan Hewat" > A : "Armel Le Bail" > Copie à : "rietveld_l@ill.fr" > Objet : Re: Rietveld website cancelled ? > > > A clear distinction having my complete agreement. (Armel) Ouf. Nous sommes d'accord enfin :-) For Armel, here are a couple of examples of automatic indexing, search-match and structure DETERMINATION from neutron powder data. Very few citations though; crystallographers largely ignored neutron powder diffraction before 1987 and Hi-Tc :-) ______________________________________________ > Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE +33.476.98.41.68 > http://www.NeutronOptics.com/hewat > ______________________________________________
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
