[Pw_forum] not converge after 100 itration

[Lorenzo Paulatto]

On 11/24/2013 08:03 PM, ehsan targholi wrote:
> dear all pw users,
> my relax calculation is not converge after 100 iteration . please help me
> to find problem in input.
> my input is :

Dear Ehsan,
there is something seriously wrong with your structure: the atoms appear
to be more or less on top of each other. If I double the size of the
first two unit cell axes it looks much more reasonable. Are you sure you
did not apply the Bohr to Agstrom conversion twice?

P.S. you normally need a small smearing to converge graphene. I think
there is a discussion of this in Phys. Rev. Lett. 93, 185503 (2004)


-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone:+33 (0)1 44275 084 / skype: paulatz
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