Sometimes, one wants to lower the symmetry because of more convenient descriptions of d-orbitals of transition metals for instance. In that case, if one still wants to maintain the higher symmetry for the geometry, one can use the SYMROT subblock to rotate the coordinates. For instance, for Fe(II)(Cl)42- with Td geometric symmetry, the Fe d-orbitals are not conveniently separated. This might be better done within C2v symmetry:
Symmetry C(2v)
QUILD
Symgeo T(d)
Symrot
-0.7071067811865475 -0.7071067811865475 0.0
-0.7071067811865475 0.7071067811865475 0.0
0.0 0.0 1.0
Subend
End
Atoms
Fe 0.000000000 0.000000000 0.000000000
Cl -1.326583289 1.326583289 1.326583289
Cl -1.326583289 -1.326583289 -1.326583289
Cl 1.326583289 1.326583289 -1.326583289
Cl 1.326583289 -1.326583289 1.326583289
End
This transforms the coordinates from Td symmetry:
Atomic coordinates atom nr x (Bohrs) y (Bohrs) z (Bohrs) x (angs) y (angs) z (angs) -------------------------------------------------------------------------------------------- FE 1 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 CL 2 -2.50688 2.50688 2.50688 -1.32658 1.32658 1.32658 CL 3 -2.50688 -2.50688 -2.50688 -1.32658 -1.32658 -1.32658 CL 4 2.50688 2.50688 -2.50688 1.32658 1.32658 -1.32658 CL 5 2.50688 -2.50688 2.50688 1.32658 -1.32658 1.32658
to C2v symmetry:
SYMMETRY C(2V) Atoms FE 0.000000000 0.000000000 0.000000000 CL 0.000000000 1.876072079 1.326583289 CL 1.876072079 0.000000000 -1.326583289 CL -1.876072079 0.000000000 -1.326583289 CL 0.000000000 -1.876072079 1.326583289 End
The particular rotation matrix to be used depends on the choice made by the user for how to represent the molecule in the lower symmetry (see ADFinput how to impose symmetry).
