[DFTB-Plus-User] Covergence issue

[Benjamin Hourahine]

Hello Georgeta,

Without the actual input its hard to diagnose this. The are several possibilities that occur to me, including for example if you are using any of the molecular dynamics modes that seed from a random number generator, or if you are reading initial charges from disc and have different starting charges in each directory and a loose SCC tolerance set.

Regards

Ben

       Dr. B. Hourahine, SUPA, Department of Physics,
     University of Strathclyde, John Anderson Building,
             107 Rottenrow, Glasgow G4 0NG, UK.
     +44 141 548 2325, benjamin.hourahine at strath.ac.uk

2013/4 THE Awards Entrepreneurial University of the Year
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________________________________
From: dftb-plus-user-bounces at mailman.zfn.uni-bremen.de [dftb-plus-user-bounces at mailman.zfn.uni-bremen.de] on behalf of Georgeta Ungureanu [georgeta27 at gmail.com]
Sent: 29 September 2014 04:57
To: dftb-plus-user at mailman.zfn.uni-bremen.de
Subject: [DFTB-Plus-User] Covergence issue

Hello

Can someone help me to understand why if I use exactly the same geometry input file, and running the same calculation several times in different directories, I get different values in total energy for a nanotube? This happens on the 5th or 6th decimal.

Thank you in advance,
Georgeta