The ABINIT Users Mailing List ( CLOSED )

[paul.boulanger@umontreal.ca]

>Why should we make this change?

Well I explained this in my previous post, but maybe I wasn't clear enough. 
In t44.in we double the cell and we rotate it. The rotation allows one to 
have one axis in the direction perpendiculare to the surface and thus enables 
to include vacuum easily (by increasing it's length).

Since the unit cell changed, we must change the way we specify the K point 
grid. If I remember correctly (!!!), this change is only in the way we 
specify it, the grid does not change. You can draw the cell and the K points 
and see it is the same for both calculations.

The reason we specify this K-point mesh shifts comes from the fact that in 
t44.in we want to compare the total energy of primitive cell and the double 
cell. Thus, we do not includ some errors coming from different K point 
sampling.

Hope this helps,

Paul