[Ifeffit] Artemis (FEFF) question

[Bruce Ravel]

On 07/12/2016 08:43 AM, Matt Newville wrote:
> Louis,
>
> On Tue, Jul 12, 2016 at 4:13 AM, Louis Forto <cforto10 at gmail.com
> <mailto:cforto10 at gmail.com>> wrote:
>
>     Dear All,
>
>     I am trying to run a FEFF calculations on a quaternary glass , when
>     I import crystalline data obtained from ICSD website and try to run
>     FEFF to calculate the scattering paths of nearest neighbour atoms
>     relative to absorbing atom, I get an error message that says
>
>     " generate one or more common positions and their occupancies sum to
>     more than 1".
>
>     I don't know how to go about this, any help , I will appreciate.
>
>
> Please post what you have done, including the file with the
> crystallographic data (CIFS file?) and the resulting feff.inp file.
>
> Not to pick on you specifically, and really this is for everyone on the
> list:  The first response to many questions is of the form "give us more
> information" and/or "we cant help you unless we understand what you are
> doing".   I see this in many forums and contexts, not just here.  In all
> such contexts,  most of the people in the "likely to answer group"
> (often a group of 1 to 3 volunteers) just view these initial, incomplete
> questions as a waste of time.  It sometimes makes some of us noticeably
> grouchy, and much less likely to want to help.  Please learn to ask
> better questions that inspire the people likely to know the answers to
> *want* to help you.   It's not a mystery how to ask better questions,
> but it is some extra work.  Then again you're asking for free help with
> your science problem, so some extra work to get a good response is
> probably worth that effort.
>
> Here is a hint: It turns out that Athena and Artemis have project files
> that contain the full information about the analysis session
> specifically so that these sessions can be shared.


Couldn't agree more.  And I have certainly been among the grouchier of late.


That said, it is likely that this is your "problem" is essential the 
same as this:

http://bruceravel.github.io/demeter/documents/Artemis/extended/dopants.html#crystal-data-with-partial-occupancy

In fact, I suspect that entire page is relevant to what you are doing.


B

-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS-II
  Building 743, Room 114
  Upton NY, 11973

  Homepage:    http://bruceravel.github.io/home/
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