[Pw_forum] Multiple issues with graphene supercell calculations

[Paolo Giannozzi]

On Nov 22, 2010, at 14:23 , Gabriele Sclauzero wrote:

> Hence, if you want more precision you probably need to use
> better k-point sampling and C-C distances.

and better (i.e. smaller) self-consistenty convergence thresholds.
The error on the energy is a quadratic function of the error on the
charge density due to imperfect self-consistency; the error on forces
is instead linear.

P.
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Paolo Giannozzi, Dept of Chemistry&Physics, Univ. Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222