Thanks a lot four your help Chris. I found late at night the CIF card for Cr(CO)6, which has exactly the same structure and has similar lattice parameters. Kind regards, Ismael.

Ismael,

You do really not need exact parameters which can is helpful in EXAFS. Can you find any references on the V-C bond length? Since CO is linear, the V-O and V-C-O scattering should be possible to roughly establish. I think a number of general inorganic textbooks might have information such as this on metal carbonyl bonding. If the lattice parameters are not too different, start with simple octahedral geometry and the quick first shell fit using V-C bond length.

buena salud,

Chris Patridge

On Wed, Mar 7, 2012 at 1:39 PM, Ismael Graff wrote:

...

Dear XAS fellows:

I have to fit EXAFS data of a nanoparticle colloidal suspension. TEM and NMR data indicate that I have nanoparticles of V(CO)_6 (vanadium hexacarbonyl). The system is orthorhombic, space group Pnma (Nr. 62), and I know the nominal values for the lattice parameters. However, I need the different atomic positions/coordinates to enter in ATOMS. Usually I get such information from a CIF (Crystallographic Information File) card. But in this case, I didn´t find it in the open data banks.

Is anyone out there that could help me?

Cheers, Ismael.

PS: A similar structure/material would also help (like Mo(CO)_6)!

-- ************************************ * Ismael Leandro Graff * * * * Universidade Federal do Paraná * * Departamento de Física, CP 19044 * * 81531-990, Curitiba, Brazil. * * Tel (office): +55 41 3361 3278 * * Tel (Lab): +55 41 3361 3427 * * Fax: +55 41 3361 3418 * * http://fisica.ufpr.br/graff * ************************************

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-- Christopher J. Patridge PhD. Contact: (315)-529-0501 _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

-- ************************************ * Ismael Leandro Graff * * * * Universidade Federal do Paraná * * Departamento de Física, CP 19044 * * 81531-990, Curitiba, Brazil. * * Tel (office): +55 41 3361 3278 * * Tel (Lab): +55 41 3361 3427 * * Fax: +55 41 3361 3418 * * http://fisica.ufpr.br/graff * ************************************