On 07/29/2013 10:49 AM, Taehoon Kim wrote:
I was thinking creating two crystal structure set using ATOMS, and perform feff calculation for each, and then choose scattering path from each atom set. I wonder whether this is an appropriate approach ? and how can I apply the ratio of each phase (let's say x is 0.6) in the fitting process ?
Hi Taehoon, That's the standard recomendation. Here are two excellent papers by familiar names on this mailing list. While neither one is quite like your specific problem, both address the topic of running Feff many times and choosing appropriate scattering paths from each calculation for the fit. http://dx.doi.org/10.1016/S0016-7037(02)00947-X http://dx.doi.org/10.1103/PhysRevB.66.224405 In any case, the trick is to add the paths together with the correct weighting. In your case, you'll need to use a multiplicative factor in the S02 math expression to reflect the fact that you have x% of Li2MnO3 and (1-x)% of LiMO2. Good luck. B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 Homepage: http://xafs.org/BruceRavel Software: https://github.com/bruceravel