Topic summary
Octahedral geometry
Extracted from the Wikipedia article Octahedral molecular geometry.
Distorted octahedral geometry
Some molecules, such as XeF6 or IF
6, have a lone pair that distorts the symmetry of the molecule from Oh to C3v. The specific geometry is known as a monocapped octahedron, since it is derived from the octahedron by placing the lone pair over the centre of one triangular face of the octahedron as a "cap" (and shifting the positions of the other six atoms to accommodate it). These both represent a divergence from the geometry predicted by VSEPR, which for AX6E1 predicts a pentagonal pyramidal shape.