[gpaw-users] Shift in the coordinates

[Ask Hjorth Larsen]

Dear Daniel

On Mon, 19 Apr 2010, Daniel Torres wrote:

> question:
> is this tag
> bulk.center(axis=2)
> commandatory in a regular slab type calculation? I mean, in a slab 
> calculation, should the atoms be centered in the Z direction?
> I personally find really confusing that you enter a set of coordinates and in 
> the output these coordinates are changed with respect to the original ones.
> Best regards
> Dani

In any non-periodic direction, atoms must not be too close to the 
boundary.  This is accomplished by centering along the non-periodic 
direction in this case.  It could be done in other ways as well.

The coordinates only change because you explicitly make them change 
through the center() call.

Regards
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