[ase-users] Bug or my misunderstanding?

[Jesper Friis]

Hi Roberto,
I guess that your choice of origin correspond to setting 2 in International Tables of Crystallography. Try 

cx = crystal(['Fe','Fe','O'],[(0.12500,  0.12500,  0.12500), (0.5, 0.5, 0.5), (0.25480,  0.25480, 0.25480)], spacegroup=227, cellpar=[a, a, a, 90, 90, 90], setting=2)

and see if that helps.

/Jesper


>-----Original Message-----
>From: ase-users-bounces at listserv.fysik.dtu.dk [mailto:ase-users-
>bounces at listserv.fysik.dtu.dk] On Behalf Of roberto.derenzi
>Sent: 15. mars 2011 19:38
>To: ase-users at listserv.fysik.dtu.dk
>Subject: [ase-users] Bug or my misunderstanding?
>
>First of all pardon me if this is just a user error.
>I am just trying out ASE, which sound as a great idea, to see if I can
>use it, as an experimentalist, for very simple minded projects. I am
>therefore a self taught beginner.
>
>I am trying to build crystal structures and to check if they are correct
>with the visualize.view command. I tried out magnetite (above the Verwey
>transition) as follows
>
>
>import ase
>from ase.lattice.spacegroup import crystal a = 8.3940
>cx=crystal(['Fe','Fe','O'],[(0.12500,  0.12500,  0.12500), (0.5, 0.5,
>0.5), (0.25480,  0.25480,  0.25480)],spacegroup=227, cellpar=[a, a, a,
>90, 90, 90])
>ase.visualize.view(cx)
>
>As I understand from the skutterudite example, the second input needs
>not be a complete basis, since a representative scaled position per each
>inequivalent atom is enough.
>However the above code does not work: oxygen atoms are certainly wrong.
>
>Where do I go wrong?
>Thanks a lot
>
>Roberto