It is thus called outer orbital
or high spin or spin free complex Thus:
In tetrahedral complexes
one s and three p orbitals
are hybridised to form four
equivalent orbitals oriented
tetrahedrally This is ill-
ustrated below for [NiCl4]
2- Here 
nickel 
is 
in 
+2
oxidation state and the ion
has 
the 
electronic
configuration 
3d
8