# dsp2 and sp3 hybrid orbital shapes in coordination chemistry

Why is $\mathrm{dsp}^2$ square planar but $\mathrm{sp}^3$ tetrahedral in shape? I am unable to find a reason anywhere. I know how to figure which hybridisation a compound is, but not why.

• How do you think you find the hybridisation of a molecule? – bon Mar 6 '16 at 13:01
• @bon I find the number of electrons, then check if the ligand is strong field or weak field. If it is strong I pair the electrons. The left over orbitals are used by the ligand, so they all get hybridised. – Mahathi Vempati Mar 6 '16 at 14:27
• ‘Stop using hybridisation to explain complexes’ is the answer to your question. – Jan Mar 21 '16 at 1:26
• Square planar usually happens if there is a reason to keep two electrons (sometimes even one) in a $\mathrm{d_{z^2}}$ orbital for stabilisation reasons. – Jan Mar 21 '16 at 1:26