Janeth,
As far as I know, Bruce is working on integraton of FEFF 8.5 into Demeter.
I also experienced reviewers asking for newer version of FEFF in the data analysis. Below was a summary of our response.
Feff 6 does not understand valence, and FEFF 8 uses a self-consistency loop to transfer charge between the atom types, resulting in something that can be related to formal valence in some situations. In the regime in which the EXAFS fit is evaluated, the photoelectron has large kinetic energy and is not particularly sensitive to the details of the potential surface. In almost all situations, FEFF 8 is a modest improvement at best over FEFF 6 for EXAFS analysis. There are some demonstrated cases where FEFF 8 is slightly better than FEFF 6 at modeling EXAFS. The most notable cases are when H is in the input file – FEFF 6 is terrible at this.
I got those information from previous discussion on the Ifeffit, see: http://www.mail-archive.com/ifeffit%40millenia.cars.aps.anl.gov/msg03381.html
 
I am not an expert, and I hope someone can help correct me if I am wrong.
 
Thanks
Guanghui
 
 
 
 
2015-06-08
Guanghui
发件人：ifeffit-request@millenia.cars.aps.anl.gov
发送时间：2015-06-08 12:00
主题：Ifeffit Digest, Vol 148, Issue 10
收件人："ifeffit"<ifeffit@millenia.cars.aps.anl.gov>
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Today's Topics: 
 
   1. how to manage Demeter with a newer FEFF version ? 
      (M. Janeth LOZANO RODRIGUEZ) 
 
 
---------------------------------------------------------------------- 
 
Message: 1 
Date: Mon, 08 Jun 2015 11:13:33 +0200 
From: "M. Janeth LOZANO RODRIGUEZ" <janeth.lozano-rodriguez@esrf.fr> 
To: ifeffit@millenia.cars.aps.anl.gov 
Subject: [Ifeffit] how to manage Demeter with a newer FEFF version ? 
Message-ID: <55755CBD.6010007@esrf.fr> 
Content-Type: text/plain; charset=utf-8; format=flowed 
 
Dear XAFS community, 
 
I wondering about the availability to use a newer FEFF version in  
Demeter. Since my knowledge only I can run FEFF6. In my case I found  
different discrepancies using FEFF6 and FEFF9 in the determination of  
bond length distances for instance. In terms of review of papers,  
reviewers ask to use a newer version instead FEFF6. These points  
strongly suggest me coming back to the obsolete Athena/Artemis version. 
 
On this obsolete version, you can download the paths generated by FEFF8,  
FEFF9. This issue is really useful when we have access to FEFF 9, for  
example.  Is there any option to implement this nice feature in Demeter?  
Does anyone have an idea how to do it? 
 
Kind regards 
Janeth Lozano 
 
 
 
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End of Ifeffit Digest, Vol 148, Issue 10 
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