Dear Wenduo Some pointers: makes sure you have good data and good models to start with. If you arn't getting low(ish) Rwp factors you arn't getting a reliable quantitative result. If you collected on flat-plate geometry it is likely you have some preferred orientation which messes up your results no-end no matter what PO correction factors you use. Also check background fitting function as this has a very marked affect on the quantitative result. Put in the background points yourself.
Most importantly you need experience and time. Practice with some well-characterised binary phases mixed in known proportions first. There isn't enough information in your request to nail this for sure but hopefully this reply may be of help. Regards, Martin Vickers Department of Chemistry University College London Telephone:+44 (0)207679 5592 Lab: +44 (0)207679 1004 _________________________________________________________________ The next generation of Windows Live is here http://www.windowslive.co.uk/get-live
