Hi Bruce,
Thank you very much for your help.
For the phase purity, we have used XRD to confirm that only Co3O4 structure was present in the sample (no other crystallized phase). So, I am pretty curious about this. I will also ask my colleague to identify the model structure in related software.
Best,
Rui
----------------------------------------------------------
Dr. Rui Si
Shanghai Institute of Applied Physics, Chinese Academy Sciences
Shanghai Synchrotron Radiation Facility
Address:
239 Zhangheng Rd, Pudong District
Shanghai 201204, China
E-mail: sirui@sinap.ac.cn
Tel: (86)21-33932079
Cell:(86)13301753969
________________________________________
发件人: Bruce Ravel [bravel@bnl.gov]
发送时间: 2014年7月15日 20:25
到: XAFS Analysis using Ifeffit; 司锐
主题: Fwd: from Rui Si at SSRF: help needed
Hi Rui,
I am CCing my answer to you and to the Ifeffit Mailing List. It's
always a good idea to use the mailing list as it greatly increases the
number of eyes that get to look at your question. If you reply to
this, please do so via the mailing list.
In the PDF file you attached, you asked these two questions:
(1) Why the second peak (ca. 3 Å) in experimental data is missing in
the Co3O4 model?
I do not know anything about your sample, so this is a tough question.
Are you certain of its phase purity? Could there be another form of
cobalt oxide present in the sample?
(2) Why need to add the “shift vector” suggested by Artemis?
Actually, no action is required and the software change the Co
core from 0.125, 0.125, 0.125 to 0.5 0.5 0.5, and keep the shift
vector as 0 0 0.
The purpose of the shift vector is explained here:
http://bruceravel.github.io/demeter/artug/atoms/space.html#multipleoriginsan...
In the case of the CIF file you attached, the shift vecotr does not
seem required. The list of atomic coordinates without the shift
vecotr looks right to me.
B
-------- Original Message --------
Subject: from Rui Si at SSRF: help needed
Date: Tue, 15 Jul 2014 07:33:31 +0000
From: 司锐