On Wednesday 14 April 2004 04:27 am, Stanislav Stoupin wrote:
As for the correlation between Ru-O variables and the background parameters, they are somewhat correlated I think
Stanislav, I think you will have to live with correlations between the oxide and the background. That is the flip side to my suggestion that you just treat the oxide as the background. (Which you and Carlo clearly explained is an undesirable thing to do.) The oxide has low frequency Fourier components and its spectrum leaks into the very low-R rang. The background spline has very low frequency components and its spectrum leak into the higher-R range. Consequently, it is hard to them apart. Oxides are "fun" that way. ;-( Would it help to impose reasonable but unvalidated prior constraints to the fit? You largest oxide/background correlations involve the oxide delta_R value. Perhaps it would be prudent to fix the R of the oxide to what you expect from bulk ruthenium oxide. That may be slightly wrong, but it might help shore up the fit. B BTW, Does the new release of Artemis seem to address the many problems you reported with your multiple data set, multiple feff calculation fits? -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 405 Naval Research Laboratory phone: (1) 202 767 2268 Washington DC 20375, USA fax: (1) 202 767 4642 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b National Synchrotron Light Source Brookhaven National Laboratory, Upton, NY 11973 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/