[DFTB-Plus-User] MD problems

[Benjamin Hourahine]

Hi,

a further point, is your initial structure geometrically relaxed? Otherwise there is a large
amount of potential energy which will 'jump out at you' during the initial phase of the MD 
calculation (possibly causing the structural problems you seem to be having).

Regards

Ben
________________________________________
From: dftb-plus-user-bounces at dftb-plus.info [dftb-plus-user-bounces at dftb-plus.info] On Behalf Of Bálint Aradi [balint.aradi at bccms.uni-bremen.de]
Sent: 04 October 2012 07:28
To: User list for DFTB+ related questions
Subject: Re: [DFTB-Plus-User] MD problems

On 10/03/2012 01:55 AM, R.Perez Garcia wrote:
> Dear Jianbing Niu,
> I am also very new in DFTB, and I work with fullerenes, but from my
> experience it is better to run smaller number of step each time, and
> then join th resulting trajectories.
> Maybe at the beginning of the simulation if your system has a lot of
> tensions is better to use a smaller time step for a few iterations to
> let the CNT to relax.
> I hope my answer is not wrong for your case
> Best regards: R
>

 Also, please note that the DivideAndConquer LAPACK routine, which is
used for the diagonalization, behaves for some cases rather "strange".
Please try either the Standard {} or the RelativelyRobust {} method for
Eigensolver. That may help.

  Best regards,

  Bálint

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