[Wien] t2g-eg splitting

[Víctor Luaña Cabal]

On Sat, Apr 11, 2015 at 11:52:11AM +0530, Vijeta Singh wrote:
> Dear Wien2k users,
> 
> I have a question concerning t2g-eg splitting. Suppose we have an
> orthorhombic system LaMnO3 as example. It has both structure Pnma and
> Pbnm.  For an orthorhombic system dxy, dyz and dxz are in t2g states and
> dx2-y2 and dz2 are in eg states. By using Pnma symmetry i am getting dxy,
> dyz and dz2 in t2g states and dxz and dx2-y2 in eg states. What is the
> reason behind this?

Vijeta,

1) The reason is symmetry
2) t2g and eg are denominations of irreducible represetations (irreps)
   of the Oh (m-3m) symmetry group. When the crystal suffers deformations
   the Oh symmetry descends in the symmetry scale.
3) The subject is very deep and I love it.

Best regards,
             Dr. Víctor Luaña
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