Hi Paul, I was hoping someone else would answer your question. I have an idea. It might not be a good idea. Look up the MSRD term that you get from Grant’s DFT parameterizations for the first Zn-S bond. Play around with the Einstein model for a Zn-S bond of the correct distance for the first Zn-S bond, to determine the correct Einstein temperature that gives the MSRD value that you looked up from Grant’s DFT. Then use that Einstein temperature and the Einstein model for the Zn-O bond of the water molecule. --It might work…. Cheers, Shelly ________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Paul Fons Sent: Thursday, July 26, 2007 9:29 PM To: XAFS Analysis using Ifeffit Subject: [Ifeffit] Debye Waller factors for Water Molecules I am analyzing some Zn organo-metallic protein complexes and have take EXAFS data at low temperature at the Zn edge. I am now in the midst of trying to fit the data. For the mean squared relative displacement terms, I am using Grant's DFT parameterizations for the Zn-cysteine system. This is working fine. In one of my complexes, I also have a water molecule within the "first shell". Does anyone have a suggestion for a reasonable MSRD term for this (at 20 K)? Paul Dr. Paul Fons Nano-Optics Reseach Team Team Leader National Institute for Advanced Industrial Science & Technology METI Center for Applied Near-Field Optics Research (CANFOR) AIST Central 4, Higashi 1-1-1 Tsukuba, Ibaraki JAPAN 305-8568 tel. +81-298-61-5636 fax. +81-298-61-2939 email: paul-fons@aist.go.jp The following lines are in a Japanese font 〒305-8562 茨城県つくば市つくば中央東 1-1-1 産業技術総合研究所 近接場光応用工学研究センター 近接場光基礎研究チーム チーム長 ポール・フォンス