[gpaw-users] a quick question about ase..

[Sampsa Riikonen]

Dear List,

A question about the unit cell and its center in ase/gpaw.

I have some molecules in a (non-periodic) box.  Then the box dimensions are:

atoms.get_cell()

array([[ 20.14820363,   0.        ,   0.        ],
        [  0.        ,  18.72969093,   0.        ],
        [  0.        ,   0.        ,  13.97714981]])


.. so that tells the length of the cell sides.

Where on earth is the info about the cell center?

Is the cell center same as the center of mass, i.e.

atoms.get_center_of_mass()

.. if this is the case, is the cell center then translated in each 
geometry optimization/molecular dynamics step
so that it corresponds to the center of mass of the atoms?

Regards,

Sampsa