[DFTB-Plus-User] Transport calculation does not converge

[Gabriele Penazzi]

Hi Alessandro,

you missed the energy unit [eV] specifier in the LevelSpacing, without
it you're setting a DOS of 1/20Hartree atom, which is basically zero,
hence everything become a numerical mess I'd guess.
Finite temperature with a metal usually helps as well. If you are in
trouble I find it useful to run a periodic boundary DFTB calculation and
see if that one converge. As the NEGF is always more critical, this
helps to understand if your problem is due to transport/bias or if the
system is particularly nasty.

Gabriele


On 04/09/2015 04:43 PM, Alessandro Pirrotta wrote:
> Dear DFTB+ users,
>
> I have upgraded my older version of the software, and I am
> experiencing some problem regarding convergence cycles.
>
> Could you give me some advice to how to improve my input files here
> attached and make the calculation converge faster?
>
> Kind regards,
> Alessandro
>
> *Alessandro Pirrotta*
> PhD student
>
>  
>
> *Faculty of Science**
> *Department of Chemistry &
> Nano-Science Center
> University of Copenhagen
> Universitetsparken 5, C321
> 2100 Copenhagen Ø
> Denmark
>
> DIR +45 21 18 11 90
> MOB +45 52 81 23 41
>
> alessandro.pirrotta at chem.ku.dk <mailto:alessandro.pirrotta at chem.ku.dk>
>
> alessandro.pirrotta at gmail.com <mailto:alessandro.pirrotta at gmail.com>
>
> www.ki.ku.dk <http://www.ki.ku.dk/>
>
>
>
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-- 
--
Dr. Gabriele Penazzi
BCCMS - University of Bremen

http://www.bccms.uni-bremen.de/
http://sites.google.com/site/gabrielepenazzi/
phone: +49 (0) 421 218 62337
mobile: +49 (0) 151 19650383

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