Scott, Bruce, Matt, Kelly, Grant and all, Thank you for your advice. I am really appreciate that.I think I have to give more detail about my analysis results and make it more clear. 1. I took the fluorescence spectrum. 2. I checked the pre-edge and post-edge lines and they looked reasonable. 3. I took the three first shell paths(Vanadium-Oxide) to fit the data. and I set amp, e0, delr, ss for the variables. 4. The degeneracy of the paths are the same as calculated by FEFF6 5. the following results amp = 0.316 +/- 0.108 e0 = 5.053 +/- 4.321 delr= 0.003 +/- 0.025 ss = -0.003 +/- 0.004 6. the correlations between amp and ss =0.88 e0 and delr = 0.86 I don't know if any other information can help to solve this problem. Thank you for your help. By the way, Grant, the papaer you mentioned, is that from " J. J. Rehr, C. H. Booth, F. Bridges, and S.I. Zabinsky, Physical review B, 49,12347, 1994"? Or other else? Can you give me more detail about that? Good day Yu-Chuan