why isnt there a dps3d hybridisation?

jd12345

I know questions of "why" regarding micriscopic world cant be generally answered but still any reason why dsp3d hybridisation isnt there.
I was studying coordination chemistry and there is outer orbital complex consisting only of outer d-orbitals and inner orbital complex consisting of only inner d-orbital so i was wondering if there is both - a dsp3d hybridisation

DrDu

What do you mean with inner and outer d orbitals. Can you provide some examples of the kind of complexes you are talking about?

jd12345

in transition metals like Fe , Mn, Co, Cr when complex are formed it either uses the 3d orbital or the 4d orbital ( talking of the 3d series metals)
there can be sp3d2 hybridisation or sp3d (here the 4d orbital is used so its outer orbital complex) while in dsp2 and d2sp3 its is inner d-orbital complex

However this is not much relevant to my question.
I was simply asking - " Why isnt there a dsp3d hybridisation"?

DrDu

Nowadays (later than, say, 1960) noone would any longer assume that 4d orbitals play any role in the bonding in transition metals from the first row, neither is d orbital hybridization relevant in main group elements.
The whole concept of outer and inner complexes is also dubious. Nowadays one would rather distinguish between high spin and low spin complexes.

DrDu

The 3d and 4d orbitals are of vastly different size and energy in the same element. Hence not both of them can contribute on an equal footing in a hybrid orbital. Generally the outer d orbitals are energetically too high and too diffuse to participate in bonding (though they contribute some percent to bonding energy as polarization functions).

jd12345

ok thank you