The ABINIT Users Mailing List ( CLOSED )

[Hua Bao <hbao@purdue.edu>]

Dear Matthieu,

Thank you for your reply. I changed the input file and use abinis to do 
the calculation. However, it just got running for a long time and no 
output was there. If I killed the job, there was even no output. The out 
file and log file were just nothing.
It this a bug or something? Or is there any compiling problem? At least 
there should be some output in the log file.

Thanks,
Hua


Matthieu Verstraete wrote:
> Hello Hua,
>
> 1) you should not set chkprim 0; use an irreducible unit cell unless 
> you are certain of what you are doing
>
> 2) The default kpt shift is 1 shift at 0.5 0.5 0.5. This could be what 
> breaks the symmetries, as you are in a hexagonal, not a cubic system. 
> Specify shiftk explicitly as 0.0 0.0 0.5 for hex systems, or even 0.0 
> 0.0 0.0. If you include  0.5 0.5 0.5, a single kpt shift is probably 
> not enough. See the tutorials and tests (in v1) on generating good kpt 
> grids.
> Depending on what you are doing the code sometimes imposes that the 
> kpt grid has the full lattice symmetry. In any case this is always a 
> good idea, and is broken if your shift can be rotated out of the kpt 
> grid by a symop.
>
> In your case the full point group symmetry appears to be P1, which I 
> think is wrong for corundum (probably your xangst are not precise 
> enough - should probably try natrd and associated variables). For the 
> kpoints the bravais lattice symmetries are used, ie for the hexagonal 
> cell.
>
> Matthieu