Non-convergence of iterative solution of linear equations ("lkain: not converged")

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Hi everyone,

I am trying to perform an NMR shielding calculation but have encountered a non-convergence in the linear equation solver.

There seems to be little documentation of options to improve convergence, nor has anyone really encountered this before in the previous threads.

Can anyone offer any advice as to what parameters can be tuned? As nothing stands out in the source code.

(I can send my input to anyone if interested, but it is massive so I've avoided listing it here. I'm testing the NMR shielding for molecular vs qm/mm embedded systems, of different sizes, and so there are alot of lines in the input file from all the point charges)

Thanks in advance,

Andy
Edited On 1:33:39 AM PDT - Mon, Apr 11th 2016 by Logsdail

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Hi Andy,

Can you send me all your input files ?

Send it directly to niri.govind@pnnl.gov

Thanks.

Best,
-Niri

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Any progress on this?

Many thanks,

Andy

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For anyone else who comes across this thread, one of the developer's has succesffuly re-run my specific case with the most recent version of NWChem (6.6), where as I was running 6.5.

I'm just recompiling the development version to ensure the problem is not build specific, after which I'll confirm that the problem is resolved.

Andy

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Just to confirm the updated version of NWChem (SVN) no longer produces these ill-effects, so problem solved and case closed. Thanks Niri!
Edited On 10:34:46 AM PDT - Sun, Jun 26th 2016 by Logsdail


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