[DFTB-Plus-User] (no subject)

[Bálint Aradi]

Dear Hegoi,

> I am trying to run a MD simulation on a system containing Ca-Si-O-H. After a 
> correct behaviour one the first 50 steps, the SCC convergency fails, and I get 
> other 50 steps later the same error reported in this message:

> Analysing my results, I show that, as Dr. Aradi said, the error appears when an 
> H atom gets to close to an O, they collapse. I have tried with 0.1 fs time 
> steps, small enough I think, and also a Non-SCC calculation. I have red that in 
> the current version there is a strange behaviour of the H atoms during MD. Is 
> this case? Is there any way to overcome the problem?

 You should use Snapshot 081217 (instead of Version 1.0.1), there the MD
error is fixed.

  Sometimes, bad repulsives in SK-files could lead to atoms getting too
close to each other. You should probably contact the authors of the
SK-files, if the error also happens with the mentioned version of DFTB+.

  Best regards

    Bálint

-- 
Dr. Bálint Aradi
Bremen Center for Computational Materials Science, University of Bremen
http://www.bccms.uni-bremen.de/en/~b_aradi


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