huge S02 value ??

mzhu＠udel.edu

5 Apr 2009 5 Apr '09

2:04 a.m.

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance. Best wishes, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

Attachments:

feff.inp (application/octet-stream — 6.6 KB)
FEFF7.exe (application/octet-stream — 686.6 KB)
Niaqueous_fl.chi (application/octet-stream — 8.7 KB)

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Frenkel, Anatoly

5 Apr 5 Apr

4:44 p.m.

Hi Mengqiang, I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0. As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8 Let me know if it helped, Anatoly ________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ?? Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance. Best wishes, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

mzhu＠udel.edu

5:47 p.m.

Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help. Best wishes, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ----

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Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" ,

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0.

As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

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# Averaged Data E:/XAFS data reduction/Ni_organic/Niaqueous_fl.avg created by SamView 8202.2409 0.0503432191908 8212.23413 0.0506953708827 8222.2525 0.0511789694428 8232.25978 0.0514279566705 8242.2558 0.0518624223769 8252.24038 0.0525789260864 8262.24992 0.0531375817955 8272.24784 0.0537167079747 8282.23396 0.0542418546975 8292.24495 0.0547551847994 8302.24396 0.0557973235846 8302.76118 0.0557101033628 8303.24153 0.0556985065341 8303.75888 0.0558634921908 8304.23935 0.0559157207608 8304.75683 0.0559655353427 8305.23741 0.055898886174 8305.75502 0.055989921093 8306.23572 0.0560606531799 8306.75347 0.0560192279518 8307.23428 0.0562393777072 8307.75215 0.0562160164118 8308.23309 0.0561975836754 8308.75109 0.0563822872937 8309.23215 0.0565039329231 8309.75027 0.0565173178911 8310.23145 0.0564906336367 8310.7497 0.056623019278 8311.231 0.0567095503211 8311.74938 0.0567882247269 8312.2308 0.0567082725465 8312.74931 0.056889321655 8313.23084 0.056946605444 8313.74948 0.0570479556918 8314.23113 0.0570488572121 8314.7499 0.0571002848446 8315.23167 0.0570758283138 8315.75057 0.0572652854025 8316.23246 0.0573980659246 8316.75149 0.0573919713497 8317.2335 0.0573230311275 8317.75265 0.057468816638 8318.23479 0.0576100423932 8318.75407 0.057746309787 8319.23632 0.0577853955328 8319.75573 0.0579555816948 8320.2381 0.058120302856 8320.75764 0.0578925535083 8321.24013 0.0581668056548 8321.7598 0.05829712376 8322.24241 0.0583414137363 8322.76221 0.0584905035794 8323.24494 0.0585640184581 8323.76487 0.058735050261 8324.24771 0.0589188709855 8324.73062 0.0589252784848 8325.25074 0.0591709502041 8325.73377 0.0592750348151 8326.25401 0.0594279393554 8326.73716 0.0597358644009 8327.25754 0.0597774200141 8327.7408 0.0600643604994 8328.26131 0.0602235011756 8328.7447 0.0604247003794 8329.26533 0.0606681294739 8329.74884 0.0610198043287 8330.2324 0.0614249669015 8330.75323 0.0618509501219 8331.23691 0.0624790862203 8331.75787 0.0636932402849 8332.24168 0.0649763420224 8332.76276 0.0663686394691 8333.24669 0.0670216009021 8333.73067 0.0670308843255 8334.25195 0.0664634555578 8334.73605 0.0659753233194 8335.25746 0.0659770593047 8335.74168 0.0662079378963 8336.26322 0.0670247301459 8336.74756 0.0677466169 8337.23196 0.0689510852098 8337.75369 0.0702973678708 8338.23821 0.0721806585789 8338.76007 0.0749269202352 8339.24471 0.0783044025302 8339.72941 0.0836063846946 8340.25146 0.0905932635069 8340.73628 0.100358486176 8341.25846 0.111847527325 8341.7434 0.12673638761 8342.26571 0.144812420011 8342.75078 0.164840593934 8343.2359 0.189977228642 8343.7584 0.215388566256 8344.24364 0.245712086558 8344.76627 0.277598172426 8345.25163 0.312181770802 8345.73705 0.348364025354 8346.25988 0.387660473585 8346.74542 0.431976109743 8347.23102 0.472981154919 8347.75404 0.519911706448 8348.23976 0.553531587124 8348.7629 0.581749677658 8349.24874 0.598809838295 8349.73464 0.603236675262 8350.25798 0.595736384392 8350.744 0.580067932606 8351.23008 0.559113204479 8351.75362 0.534161090851 8352.23981 0.513237476349 8352.76348 0.491190701723 8353.2498 0.475665122271 8353.73618 0.461076319218 8354.26003 0.44764572382 8354.74653 0.436856925488 8355.23309 0.424854964018 8355.75714 0.414566487074 8356.24382 0.403525471687 8356.73056 0.393537521362 8357.2548 0.382946223021 8357.74166 0.374857634306 8358.26604 0.367622852325 8358.75302 0.361497223377 8359.24005 0.357017964125 8359.76462 0.352981805801 8360.25178 0.34984382987 8360.739 0.347904413939 8361.26376 0.3453335464 8361.7511 0.343954563141 8363.77606 0.33702352643 8365.31421 0.330680251122 8366.89047 0.322264581919 8368.54245 0.312394797802 8370.1951 0.302227884531 8371.88601 0.292130529881 8373.65282 0.284876316786 8375.4204 0.282420456409 8377.22638 0.286087781191 8379.07081 0.295591473579 8380.95374 0.309234887362 8382.91292 0.325743764639 8384.87304 0.341233998537 8386.87182 0.35518103838 8388.90933 0.366731077433 8390.98562 0.375733524561 8393.10074 0.381860047579 8395.25476 0.385798722506 8397.40992 0.387585878372 8399.6419 0.388429731131 8401.91296 0.388202726841 8404.22317 0.387039572001 8406.53469 0.385434269905 8408.92337 0.382780224085 8411.35139 0.37941879034 8413.78086 0.375138401985 8416.28777 0.370015978813 8418.79621 0.365214079618 8421.34423 0.360621899366 8423.96997 0.355812817812 8426.5974 0.35168170929 8429.26463 0.348526418209 8431.97173 0.346954137087 8434.7188 0.347031861544 8437.5059 0.348675727844 8440.33311 0.351105034351 8443.20052 0.354547977448 8446.06994 0.358157724142 8449.01796 0.361708432436 8452.00642 0.364646136761 8454.99706 0.367507129908 8458.02827 0.370203047991 8461.13853 0.372706145048 8464.25115 0.374911367893 8467.4046 0.376580387354 8470.59897 0.378288060427 8473.83435 0.379800200462 8477.11083 0.381045907736 8480.42852 0.38195297122 8483.74888 0.382700711489 8487.14922 0.38271227479 8490.55237 0.382056862116 8494.03577 0.380995690823 8497.52211 0.38030987978 8501.05018 0.379144132137 8504.62009 0.378174126148 8508.23193 0.377518713474 8511.84693 0.377044290304 8515.54294 0.376703381538 8519.2812 0.37665694952 8523.02285 0.376857817173 8526.8069 0.377554535866 8530.63347 0.378239005804 8534.50268 0.379017233849 8538.41464 0.380187660456 8542.36946 0.381414294243 8546.32805 0.382630646229 8550.36892 0.383927434683 8554.41371 0.385468482971 8558.50177 0.38671079278 8562.63322 0.388175427914 8566.80817 0.389347910881 8570.98731 0.390421718359 8575.24962 0.391160845757 8579.51629 0.39192545414 8583.82689 0.392668396235 8588.18155 0.393110185862 8592.58041 0.393247365952 8597.02359 0.393335938454 8601.4715 0.393469333649 8605.96392 0.393436104059 8610.50099 0.393508255482 8615.08283 0.393732249737 8619.7096 0.39393928647 8624.34148 0.394159913063 8629.05848 0.394705355167 8633.78077 0.39538025856 8638.54847 0.395932585001 8643.32158 0.396743118763 8648.18048 0.397644668818 8653.04499 0.398692518473 8657.95539 0.399691611528 8662.91185 0.400655061007 8667.91451 0.401881337166 8672.92311 0.402921974659 8677.97812 0.403703838587 8683.0797 0.405089437962 8688.22801 0.406228214502 8693.42321 0.408054947853 8698.6248 0.407343238592 8703.87349 0.408338308334 8709.16946 0.409054726362 8714.47205 0.409889370203 8719.82214 0.410414457321 8725.2199 0.411167293787 8730.6655 0.411896407604 8736.15911 0.412471413612 8741.65982 0.413297116756 8747.20878 0.414116382599 8752.80616 0.414591550827 8758.4109 0.41539311409 8764.06431 0.41607311368 8769.76657 0.417302787304 8775.51785 0.418299645185 8781.27689 0.419074982405 8787.0852 0.420488893986 8792.94298 0.420116811991 8798.80879 0.421969741583 8804.72432 0.423195332289 8810.68977 0.424288362265 8816.70532 0.425644159317 8822.72931 0.426800459623 8828.80367 0.428035140038 8834.88663 0.429196715355 8841.06228 0.430980712175 8847.24679 0.430583775043 8853.44019 0.431932598352 8859.72694 0.433207005262 8866.02286 0.434144616127 8872.32797 0.435127168894 8878.68469 0.43594378233 8885.09324 0.437184542418 8891.55382 0.438168525696 8898.02405 0.439386665821 8904.54661 0.440207213163 8911.12172 0.441409856081 8917.70679 0.44283464551 8924.34471 0.443438112736 8930.99277 0.444863021374 8937.694 0.447270870209 8944.4486 0.44786721468 8951.21368 0.449026316404 8958.03245 0.4505623281 8964.90514 0.451538711786 8971.78866 0.453072309494 8978.72642 0.454423695803 8985.67519 0.455706417561 8992.67853 0.457181721926 8999.73667 0.458623111248 9006.80619 0.460347890854 9013.93085 0.461145192385 9021.06707 0.462838590145 9028.25877 0.464187204838 9035.5062 0.465361386538 9042.76556 0.466764986515 9050.081 0.468260288239 9057.40857 0.469603300095 9064.79257 0.47124055028 9072.18893 0.472517997026 9079.64206 0.474343031645 # data from ifeffit #------------------------ # energy samnorm 8202.2409 0.74866890E-03 8212.2341 0.22279024E-03 8222.2525 0.15032521E-03 8232.2598 -0.73002743E-03 8242.2558 -0.96499940E-03 8252.2404 -0.22785937E-03 8262.2499 -0.39712892E-04 8272.2478 0.21939172E-03 8282.2340 0.29517591E-03 8292.2450 0.32612754E-03 8302.2440 0.21515093E-02 8302.7612 0.17673362E-02 8303.2415 0.16458539E-02 8303.7589 0.21164109E-02 8304.2393 0.22111342E-02 8304.7568 0.22913205E-02 8305.2374 0.19833304E-02 8305.7550 0.22031007E-02 8306.2357 0.23603772E-02 8306.7535 0.21315448E-02 8307.2343 0.27945818E-02 8307.7522 0.26268715E-02 8308.2331 0.24822047E-02 8308.7511 0.30186185E-02 8309.2321 0.33478591E-02 8309.7503 0.33044281E-02 8310.2314 0.31317991E-02 8310.7497 0.34908477E-02 8311.2310 0.37010643E-02 8311.7494 0.38783107E-02 8312.2308 0.35255790E-02 8312.7493 0.40488223E-02 8313.2308 0.41599639E-02 8313.7495 0.44136311E-02 8314.2311 0.43341693E-02 8314.7499 0.44190654E-02 8315.2317 0.42539472E-02 8315.7506 0.48049896E-02 8316.2325 0.51708277E-02 8316.7515 0.50612911E-02 8317.2335 0.47459579E-02 8317.7527 0.51491704E-02 8318.2348 0.55432234E-02 8318.7541 0.59140699E-02 8319.2363 0.59632551E-02 8319.7557 0.64483502E-02 8320.2381 0.69212327E-02 8320.7576 0.60638822E-02 8321.2401 0.69060414E-02 8321.7598 0.72562614E-02 8322.2424 0.73227114E-02 8322.7622 0.77360317E-02 8323.2449 0.79008814E-02 8323.7649 0.83879280E-02 8324.2477 0.89243107E-02 8324.7306 0.88628107E-02 8325.2507 0.96009243E-02 8325.7338 0.98683269E-02 8326.2540 0.10293658E-01 8326.7372 0.11247262E-01 8327.2575 0.11297365E-01 8327.7408 0.12179913E-01 8328.2613 0.12625622E-01 8328.7447 0.13219171E-01 8329.2653 0.13948213E-01 8329.7488 0.15047676E-01 8330.2324 0.16326774E-01 8330.7532 0.17669073E-01 8331.2369 0.19697336E-01 8331.7579 0.23689099E-01 8332.2417 0.27918105E-01 8332.7628 0.32506434E-01 8333.2467 0.34615003E-01 8333.7307 0.34559710E-01 8334.2519 0.32559815E-01 8334.7360 0.30833521E-01 8335.2575 0.30746747E-01 8335.7417 0.31436282E-01 8336.2632 0.34086773E-01 8336.7476 0.36424470E-01 8337.2320 0.40381842E-01 8337.7537 0.44807477E-01 8338.2382 0.51041184E-01 8338.7601 0.60162607E-01 8339.2447 0.71406607E-01 8339.7294 0.89104823E-01 8340.2515 0.11244338 8340.7363 0.14510243 8341.2585 0.18352604 8341.7434 0.23334815 8342.2657 0.29383405 8342.7508 0.36085694 8343.2359 0.44498559 8343.7584 0.53000057 8344.2436 0.63146481 8344.7663 0.73812351 8345.2516 0.85379541 8345.7370 0.97465580 8346.2599 1.1039955 8346.7454 1.2534165 8347.2310 1.4558256 8347.7540 1.5152686 8348.2398 1.6635977 8348.7629 1.7558737 8349.2487 1.8100463 8349.7346 1.8260377 8350.2580 1.8001995 8350.7440 1.7478613 8351.2301 1.6763827 8351.7536 1.5965906 8352.2398 1.5235524 8352.7635 1.4504664 8353.2498 1.3965835 8353.7362 1.3480193 8354.2600 1.3031848 8354.7465 1.2661193 8355.2331 1.2301967 8355.7571 1.1906469 8356.2438 1.1542786 8356.7306 1.1227526 8357.2548 1.0893734 8357.7417 1.0580964 8358.2660 1.0320476 8358.7530 1.0133259 8359.2401 0.99777235 8359.7646 0.98414301 8360.2518 0.97415388 8360.7390 0.96646725 8361.2638 0.96016790 8361.7511 0.95453042 8363.7761 0.92922715 8365.3142 0.90724362 8366.8905 0.87863167 8368.5425 0.84509322 8370.1951 0.81046205 8371.8860 0.77637779 8373.6528 0.75157870 8375.4204 0.74286632 8377.2264 0.75425740 8379.0708 0.78509230 8380.9537 0.82968666 8382.9129 0.88351180 8384.8730 0.93403878 8386.8718 0.97937259 8388.9093 1.0167099 8390.9856 1.0454975 8393.1007 1.0648373 8395.2548 1.0767591 8397.4099 1.0817341 8399.6419 1.0834259 8401.9130 1.0816086 8404.2232 1.0767458 8406.5347 1.0703019 8408.9234 1.0604813 8411.3514 1.0482515 8413.7809 1.0330117 8416.2878 1.0151076 8418.7962 0.99820302 8421.3442 0.98195439 8423.9700 0.96506836 8426.5974 0.95035539 8429.2646 0.93890704 8431.9717 0.93255701 8434.7188 0.93165768 8437.5059 0.93576013 8440.3331 0.94253553 8443.2005 0.95243412 8446.0699 0.96292903 8449.0180 0.97317306 8452.0064 0.98143054 8454.9971 0.98933629 8458.0283 0.99671630 8461.1385 1.0034226 8464.2512 1.0090894 8467.4046 1.0131313 8470.5990 1.0171516 8473.8343 1.0205454 8477.1108 1.0230409 8480.4285 1.0244859 8483.7489 1.0252984 8487.1492 1.0237492 8490.5524 1.0200814 8494.0358 1.0151752 8497.5221 1.0112447 8501.0502 1.0059237 8504.6201 1.0011603 8508.2319 0.99739934 8511.8469 0.99422641 8515.5429 0.99146649 8519.2812 0.98959352 8523.0228 0.98855497 8526.8069 0.98898593 8530.6335 0.98945848 8534.5027 0.99020482 8538.4146 0.99207124 8542.3695 0.99414173 8546.3281 0.99618088 8550.3689 0.99844948 8554.4137 1.0013504 8558.5018 1.0034515 8562.6332 1.0060917 8566.8082 1.0078872 8570.9873 1.0092721 8575.2496 1.0096633 8579.5163 1.0100661 8583.8269 1.0103443 8588.1815 1.0097060 8592.5804 1.0081044 8597.0236 1.0062959 8601.4715 1.0046069 8605.9639 1.0024547 8610.5010 1.0005729 8615.0828 0.99910808 8619.7096 0.99760404 8624.3415 0.99618090 8629.0585 0.99563628 8633.7808 0.99547682 8638.5485 0.99502246 8643.3216 0.99526517 8648.1805 0.99579209 8653.0450 0.99671647 8657.9554 0.99746937 8662.9119 0.99811472 8667.9145 0.99949054 8672.9231 1.0003110 8677.9781 1.0004227 8683.0797 1.0021154 8688.2280 1.0031480 8693.4232 1.0020222 8698.6248 1.0016700 8703.8735 1.0021403 8709.1695 1.0018951 8714.4721 1.0018382 8719.8221 1.0009846 8725.2199 1.0006483 8730.6655 1.0002251 8736.1591 0.99940594 8741.6598 0.99927260 8747.2088 0.99904101 8752.8062 0.99789258 8758.4109 0.99753021 8764.0643 0.99694079 8769.7666 0.99783260 8775.5179 0.99810003 8781.2769 0.99787516 8787.0852 0.99848430 8792.9430 0.99769183 8798.8088 0.99807384 8804.7243 0.99864412 8810.6898 0.99905665 8816.7053 1.0000658 8822.7293 1.0006060 8828.8037 1.0012944 8834.8866 1.0017560 8841.0623 1.0012783 8847.2468 0.99994259 8853.4402 1.0007973 8859.7269 1.0014472 8866.0229 1.0011766 8872.3280 1.0009244 8878.6847 1.0002879 8885.0932 1.0006976 8891.5538 1.0004837 8898.0240 1.0008309 8904.5466 1.0000384 8911.1217 1.0002969 8917.7068 1.0011633 8924.3447 0.99969244 8930.9928 1.0005109 8937.6940 1.0013619 8944.4486 1.0024662 8951.2137 1.0024555 8958.0325 1.0034546 8964.9051 1.0028690 8971.7887 1.0038083 8978.7264 1.0042079 8985.6752 1.0044034 8992.6785 1.0050903 8999.7367 1.0056465 9006.8062 1.0069577 9013.9309 1.0057072 9021.0671 1.0068772 9028.2588 1.0070737 9035.5062 1.0067630 9042.7656 1.0070562 9050.0810 1.0075578 9057.4086 1.0076342 9064.7926 1.0084595 9072.1889 1.0083069 9079.6421 1.0095730

Frenkel, Anatoly

6 Apr 6 Apr

1:54 a.m.

Hi, Very strange. Your data are indeed more intense in k-space than mine, after they are perfectly aligned. Since you have some systematic noise in the end of the k-range, I wonder if you should be better off remeasuring this system, instead of trying to brain storm why it gives high S02. Of course, it could mean that my data are wrong and your are right. But this is not easy to troubleshoot. If you are in doubt, better to look at other comparisons, between reference materials that you collected during the same run and those that you had measured earlier. Anatoly ________________________________ From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sun 4/5/2009 1:47 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ?? Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help. Best wishes, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ----

...

Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" ,

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0.

As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

mzhu＠udel.edu

3:51 a.m.

Hello Anatoly, In addition to Ni aqueous solutions, I and my former group members also collected EXAFS of solutions of many Ni-organic complexes which are octahedral (O)in first shell at differet time and on differet beamlines. All the fitting resulted in high S02 values although bond distances are correct and fitting goodness is good as well. My collegue and I also found that a S02 of 0.85 was obtained from the fitting of Ni aqueous solution if we used feff files created from the artificial single Ni-O path instead of from crystal structures using Feff 6. Using files created from Feff 7 with single Ni-O path resulted in a high value close to 1. I am thinking if this high S02 value comes from the Feff code. The versions of Feff that I use is Feff 7.00 and Feff 6. I am wondering if you can send me your EXAFS data of Ni aqueous solution and the Feff you used to creat these files. Thanks for your time and efforts. Best wishes, Mengqiang ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ----

...

Date: Sun, 5 Apr 2009 21:54:41 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit"

Hi, Very strange. Your data are indeed more intense in k-space than mine, after they are perfectly aligned. Since you have some systematic noise in the end of the k-range, I wonder if you should be better off remeasuring this system, instead of trying to brain storm why it gives high S02.

Of course, it could mean that my data are wrong and your are right. But this is not easy to troubleshoot. If you are in doubt, better to look at other comparisons, between reference materials that you collected during the same run and those that you had measured earlier.

Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sun 4/5/2009 1:47 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ??

Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

---- Original message ----

...
Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" ,

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0.

As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

________________ TNEF8520.rtf (16k bytes) ________________ _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

Kropf, Arthur Jeremy

3:55 p.m.

If the amplitudes in chi(k) are different, I would suggest that in the set with the larger amplitude the logarithm of the ratio was not taken when importing the data. Jeremy -----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly Sent: Sun 4/5/2009 8:54 PM To: XAFS Analysis using Ifeffit Subject: RE: [Ifeffit] huge S02 value ?? Hi, Very strange. Your data are indeed more intense in k-space than mine, after they are perfectly aligned. Since you have some systematic noise in the end of the k-range, I wonder if you should be better off remeasuring this system, instead of trying to brain storm why it gives high S02. Of course, it could mean that my data are wrong and your are right. But this is not easy to troubleshoot. If you are in doubt, better to look at other comparisons, between reference materials that you collected during the same run and those that you had measured earlier. Anatoly _____ From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sun 4/5/2009 1:47 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ?? Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help. Best wishes, Mengqiang Zhu ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ----

...

Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" ,

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0.

As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

mzhu＠udel.edu

7 Apr 7 Apr

6:21 p.m.

Hello Jeremy, Thanks for your reply. Did you mean that the logrithum of I0/I was not taken? I checked my spectra again and I am sure I did. Best wishes, Mengqiang ----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html ---- Original message ----

...

Date: Mon, 6 Apr 2009 10:55:02 -0500 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Kropf, Arthur Jeremy" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" , "XAFS Analysis using Ifeffit"

If the amplitudes in chi(k) are different, I would suggest that in the set with the larger amplitude the logarithm of the ratio was not taken when importing the data.

Jeremy

-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of Frenkel, Anatoly Sent: Sun 4/5/2009 8:54 PM To: XAFS Analysis using Ifeffit Subject: RE: [Ifeffit] huge S02 value ??

Hi, Very strange. Your data are indeed more intense in k-space than mine, after they are perfectly aligned. Since you have some systematic noise in the end of the k-range, I wonder if you should be better off remeasuring this system, instead of trying to brain storm why it gives high S02.

Of course, it could mean that my data are wrong and your are right. But this is not easy to troubleshoot. If you are in doubt, better to look at other comparisons, between reference materials that you collected during the same run and those that you had measured earlier.

Anatoly

_____

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sun 4/5/2009 1:47 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ??

Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

---- Original message ----

...
Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" ,

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to the pre-edge region, and I suspect, therefore, it is where you chose your E0.

As a result, the entire, very intense, main absorption peak became a part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either. Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

Kropf, Arthur Jeremy

6:36 p.m.

Yes. That is what I meant. Nonetheless, it was worth checking, just in case. Jeremy Chemical Sciences and Engineering Division Argonne National Laboratory Argonne, IL 60439 Ph: 630.252.9398 Fx: 630.252.9917 Email: kropf@anl.gov

...

-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of mzhu@udel.edu Sent: Tuesday, April 07, 2009 1:21 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ??

Hello Jeremy, Thanks for your reply. Did you mean that the logrithum of I0/I was not taken? I checked my spectra again and I am sure I did.

Best wishes,

Mengqiang

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

...
Date: Mon, 6 Apr 2009 10:55:02 -0500 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Kropf, Arthur Jeremy" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit" , "XAFS Analysis using Ifeffit"

If the amplitudes in chi(k) are different, I would suggest

---- Original message ---- that in the set with the larger amplitude the logarithm of the ratio was not taken when importing the data.

...
Jeremy

-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of

...
Anatoly Sent: Sun 4/5/2009 8:54 PM To: XAFS Analysis using Ifeffit Subject: RE: [Ifeffit] huge S02 value ??

Hi, Very strange. Your data are indeed more intense in k-space

Frenkel, than mine, after they are perfectly aligned. Since you have some systematic noise in the end of the k-range, I wonder if you should be better off remeasuring this system, instead of trying to brain storm why it gives high S02.

...
Of course, it could mean that my data are wrong and your are

right. But this is not easy to troubleshoot. If you are in doubt, better to look at other comparisons, between reference materials that you collected during the same run and those that you had measured earlier.

...
Anatoly

_____

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sun 4/5/2009 1:47 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] huge S02 value ??

Hello Anatoly, The E0 I used for EXAFS extraction is 8344 ev, which is

located in the half of the edge jump. I tried a higher E0 as you suggested, such as 8347 ev, but I still got a huge S02 value. In the attchment is the mu(E) and average data of Ni solution. I very appreciate your help.

...
Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

---- Original message ----

...
Date: Sun, 5 Apr 2009 12:44:13 -0400 From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of "Frenkel, Anatoly" ) Subject: Re: [Ifeffit] huge S02 value ?? To: "XAFS Analysis using Ifeffit"

...
...

Hi Mengqiang,

I have done fits of aqueous solution of NiSO4 before and obtained S02 of 0.8 for the octahedrally coordinated Ni-O shell. You did not send the mu(E) data, just chi(k), so I was not able to compare my and your raw data fully, just in k-space. Here is what I found: my data is in perfect agreement in k-space with yours, only if I move E0 down to

...
...
As a result, the entire, very intense, main absorption peak

became a

...
part of your EXAFS, increasing the intensity of the k-space signal (since it became the first half-cycle of the EXAFS oscillation), and thus you got such a large S02. If you move your E0 to half-the edge jump, your result will be the same as mine, 0.8

Let me know if it helped, Anatoly

________________________________

From: ifeffit-bounces@millenia.cars.aps.anl.gov on behalf of mzhu@udel.edu Sent: Sat 4/4/2009 10:04 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] huge S02 value ??

Hello everyone, I have been fitting EXAFS of NiSO4 aqueous solution. The feff files were created from Ni(OH)2 using Feff7.00. During

, the pre-edge region, and I suspect, therefore, it is where you chose your E0. the fitting, coordination number was fixed as 6. The S02 derived from fitting is 1.22. I tried other materials for creating feff files, such as NiCO3 and NiPO4, and I got the similar S02 values. I also tried Feff6, it did not result in a reasonable S02 value, either.

...
...
Anyone can tell me why it led to such high S02 value? The data file and feff input file (Feff 7) are attached. Thanks in advance.

Best wishes,

Mengqiang Zhu

----------------------- Mengqiang Zhu Ph.D Candidate Environmental Soil Chemistry Department of Plant and Soil Sciences University of Delaware 152 Townsend Hall Newark, DE 19716 http://ag.udel.edu/soilchem/zhu.html

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

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Frenkel, Anatoly
Kropf, Arthur Jeremy
mzhu＠udel.edu

huge S02 value ??

mzhu＠udel.edu

Frenkel, Anatoly

mzhu＠udel.edu

Frenkel, Anatoly

mzhu＠udel.edu

Kropf, Arthur Jeremy

mzhu＠udel.edu

Kropf, Arthur Jeremy

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