Geometry of a Compound?

Question

I was wondering how do I find the geometry of hexafluoroaluminate, AlF6 3- ? I was trying to use the orbital here to solve it I see its d2sp3 which is related to octahedral geometry, but would about the 3 extra electrons?

Answer 1

Aluminium has 3 valence electrons; each fluorine has 7, for a total of 3+6*7+3 = 48 electrons. Place 6 on each fluorine (three lone pairs) and two on each Al-F bond (total 6 single bonds). There are no leftover electrons. Hence Al is surrounded by 6 electron pairs and the geometry is octahedral.

The hybridization theory is useful in organic chemistry, but should be used carefully when attempting to predict the geometry around an atom. This direct approach is much more useful in my opinion.