[DFTB-Plus-User] Molecular Dynamics ERROR

Bálint Aradi balint.aradi at bccms.uni-bremen.de
Wed Dec 2 11:22:54 CET 2009


Dear Mandelle Danser,

Mandelle Danser wrote:
> I am trying to run molecular dynamics simulations and within the run an
> error message comes up saying 'failure in diagonalisation routine dsygvd,
> non-positive definite overlap!'  Is there any way to get around this?  What
> must be changed in the input to avoid such errors?
> Thank you.

 This usually happens, if your MD simulation results in a strange
geometry, where you encounter basis superposition error. The
straightforward way to work around it would be either to use the
Standard Lapack diagonalizer, instead of divide and conquer, as latter
is less picky about the overlap matrix. If even that one fails, you
should modify the geometry a little bit, and start again.

  Best regards

  Bálint

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


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 252 bytes
Desc: OpenPGP digital signature
Url : http://www.dftb-plus.info/pipermail/dftb-plus-user/attachments/20091202/cb8aa3fd/attachment.pgp 


More information about the DFTB-Plus-User mailing list