Hi All, A couple of points about lattice parameter constraints: 1) Beware of using "damping"; it isn't needed especially for lattice parameters in Rietveld refinements and it will mess up the intent of constraints if not very carefully used. 2) The constraints are on the reciprocal metric tensor elements and must only include those that are refined for the Laue symmetry. So for cubic only RM11 is available for a constraint to another phase. Best, Bob Von Dreele
________________________________ From: Andreas Leineweber [mailto:[EMAIL PROTECTED] Sent: Wed 11/15/2006 5:35 AM To: rietveld_l@ill.fr Subject: Re: Cell parameter constrain Hello all, I can confirm that problem. I recall that there were constraints imposed, but somehow with different factors than intended... However, the problem was not that severe that I solved it. Best regards Andreas Davide Levy wrote: Hi, I am trying to constrain the cell parameters of two phases (cubic and triclinic) in GSAS. I have given the constrain of the reciprocal metric tensor, but when I refine the cell parameters are not constrained. how con do it correctly? Davide Davide Levy Dipartimento di Scienze Mineralogiche e Petrologiche Universita' di Torino V. Valperga Caluso 35 I-10125 Torino Italy Phone: +(39)0116705122 -- Dr. Andreas Leineweber Max-Planck-Institut fuer Metallforschung Heisenbergstrasse 3 70569 Stuttgart Germany Tel. +49 711 689 3365 Fax. +49 711 689 3312 e-mail: [EMAIL PROTECTED] home page of department: http://www.mf.mpg.de/de/abteilungen/mittemeijer/english/index_english.htm
