[Wien] q re: 'local coordinates' and px, py, pz

[Peter Blaha]

> In case.outputs I have:
>  ATOM:          -4
> O Oxygen   operation #  1     1
> O Oxygen   operation #  6     m n z
>   pointgroup is m (neg. iatnr!!)
>   axes should be: m n z
>   z-rotation vector:  0.0000  0.0000  1.0000
>   y-rotation vector:  0.7071 -0.7071  0.0000    0
> LOCAL ROT MATRIX:       NEW                                OLD
>            1.0000000 0.0000000 0.0000000      1.0000000 0.0000000 0.0000000
>            0.0000000 1.0000000 0.0000000      0.0000000 1.0000000 0.0000000
>            0.0000000 0.0000000 1.0000000      0.0000000 0.0000000 1.0000000
>
> (This was what I meant when I said WIEN2k does not suggest a local
> rotation matrix.) I take it to mean that since there is only a mirror
> operation, the axis with highest symmetry is that which is perpendicular
> to the mirror plane (the plane containing the Cu  2x Ti and O atoms) and
> hence that is designated the z axis  ?

> Further do the y and z-rotation vectors (shown above) strictly relate to
> the first listed of the equivalent positions of the O atom in the
> case.struct file ?

All quantities relate always to the FIRTS atom in the list of an equivalet set.


> > I cannot answer your specific question (x along Cu,...?) without
> > case.outputs (and case.struct), but I think it is fairly straight forward
> > with the information in your case.outputs.
>
> I attach case.outputs and case.struct and would be very grateful if you
> could guide me to the answer as to the local orientations of px, py and
> pz for the O atom.

Since the local rotation matrix is the unit matrix, px points into the
crystallographic x direction, py ... and so on. It is the "most trivial" case.


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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