[Wien] antiferroelectric distortion

[Andrei Postnikov]

On Thu, 9 Sep 2004 arnaud.vasseur at caramail.com wrote:

| Dear wien users.
|
| Actually I have a ReO3 cubic, Fm3m structure. With one Re at (0,0,0) and 3 O at (0,0,0.5); (0,0.5,0); (0.5,0,0). I would like to study phase transition from the cubic structure to the tetragonal one. To do this: I optimized c/a (by changing c in the struct file, tetragonal distortion with #sym.op=0) and this has worked well. At this stage I want to do an antiferroelectric displacement of the Re element.
| Can you pleas indicate me if this possible?

Yes.
You'd need to double the cell, first figuring out how exactly
(depending on the actual antiferroelectric displacement pattern);
the symmetry will then reduce (to orthorhombic?)

Andrei Postnikov

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