The ABINIT Users Mailing List ( CLOSED )

[Hongyi Zhao <hongyi.zhao@gmail.com>]

On Fri, Apr 20, 2007 at 09:43:03AM +0200, paul.boulanger@umontreal.ca wrote:
> Hi again,
> 
> If you inspect carefully the tutorial, you will find that in t44.in you are 
> not calculating the properties of the Al slab, but of the Al bulk crystal. 
> This step is included only to check that the double cell is well defined: 
> the total energy is only the double of the energy of the primitive cell. 
> Since we are doing a bulk crystal we use a three-dimensional K point mesh:
> 
> ngkpt 4 4 4 

But from the input file t41.in to t43.in, the parameters nshiftk and 
shiftk are all the same as follows:

-------
nshiftk 4 
shiftk 0.5 0.5 0.5
       0.5 0.0 0.0
       0.0 0.5 0.0
      0.0 0.0 0.5
-------

In the t44.in, the parameters nshiftk and·shiftk have been changed into 
the follows:

-------
nshiftk 2
shiftk  0.5 0.0 0.5
        0.0 0.5 0.5
-------

Why should we make this change?

Thanks in advance.
---
Hongyi Zhao 
GnuPG DSA: 0xD108493B