[Ifeffit] FOLP error in Feff calculation

Kewei Zhao keweiz at princeton.edu
Tue May 26 17:32:54 CDT 2020


Dear Matthew,

Thanks for the suggestion.

The cluster structure is generated from molecular dynamics trajectories, and I just picked a random one out of 10k+ clusters. The Ca-Cl distance varies between 3-8 A. And not all calculations of Cl-containing clusters return such error.

The cluster is not charge-neutral. But using the ION card did not solve the problem.

Best,

Kewei



--

Kewei Zhao

Ph.D. Student

Myneni Lab

Princeton University



From: Matthew Marcus<mailto:mamarcus at lbl.gov>
Sent: Tuesday, May 26, 2020 5:50 PM
To: Kewei Zhao<mailto:keweiz at princeton.edu>
Subject: Re: [Ifeffit] FOLP error in Feff calculation



Here is your feff.inp, reworked as follows:
1.      Subtract the position of Atom 0 (Ca) from all others.
2.      Sort on distance from Ca, which is the new column.

As you can see, a lot of the distances are way too close to Ca, which is a big atom.  That may be part of the problem.

Your lone Cl is almost 7A from the Ca.  Was that intended?  It does seem odd that this only happened when you included that distant
atom.  Also, I didn't count - is this cluster charge-neutral?
Sincerely,
     Matthew Marcus

On 5/26/2020 1:10 PM, Kewei Zhao wrote:
> Dear colleagues,
>
> I'm using Feff to simulate the EXAFS of an aqueous Ca cluster. But I got this error when I tried to include Cl in the structure (potential type 0 is Ca, 1 is O, 2 is H, and 3 is Cl):
>
>   Feff 8.50L
>   Ca in water
>   Calculating potentials ...
>      free atom potential and density for atom type    0
>      free atom potential and density for atom type    1
>      free atom potential and density for atom type    2
>      free atom potential and density for atom type    3
>      initial state energy
>      overlapped potential and density for unique potential    0
>      overlapped potential and density for unique potential    1
>      overlapped potential and density for unique potential    2
>      overlapped potential and density for unique potential    3
>      muffin tin radii and interstitial parameters
>   FOLP for POTENTIAL type   3 is too big.
>   Reduce overlap using FOLP and rerun
> MOVRLP-1
>
> If I change the type 3 atom to other elements or move its position, the error is gone. However, I do not want to change the input structure. Including FOLP or AFOLP cards in the input file did not work. Is there anyway to bypass this error? Please find my input file attached.
>
> Thanks,
> Kewei Zhao
>
> --
>
> Kewei Zhao
>
> Ph.D. Student
>
> Myneni Lab
>
> Princeton University
>
>
>
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