[Pw_forum] Relaxation of AlN surface

[Paolo Giannozzi]

lan haiping wrote:

> How do you think about the thread for electron scf : conv_thr = 1.D-6 ?

I think it is quite good. Consider that it will be reduced during
structural optimization. What is meaningless (way too small) is
the following:
    etot_conv_thr = 1.d-8
This is however irrelevant for scf convergence.

> And only gamma k-point sampling for your cell

only gamma may be sufficient or not, one has to verify.
I would try a denser grid in the xy direction. The main
problem  in this case is however that the system is treated
as an insulator. It should be sufficient to add a few more
bands and a broadening, as explained by Eyvaz

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy