[Pw_forum] question about correctness

[Lorenzo Paulatto]

On 04/08/2014 03:26 PM, 薛诗川 wrote:
> Sorry to disturb but i have another question:
> when testing AUSURF112 using QE_CPU 5.0.2,
> it stopped less than 10 min.
> because in input file : electron_maxstep = 2
> so after 2 scf iter, it stopped.
> but checking the output i found that it says after 2 iter ,convergence 
> NOT ACHIEVED
> then i am wondering since convergence not achieved, how can i 
> guarantee its correctness?
>

Dear 薛诗川,
you cannot.

If you want a correct result you must converge it.

best regards

-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
+33 (0)1 44 275 084 / skype: paulatz
http://www-int.impmc.upmc.fr/~paulatto/
23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05