The complex, [Ni(CN)4]2-, has:
Octahedral structure
Tetrahedral structure
Linear structure
Square planar Structure
The [Ni(CN)4]2- involve dsp2 hybridization and hence square planar geometry.
Solid SO3 exists as:
The geometries of the ammonia complexes of Ni2+, Pt2+ and Zn2+, respcetively, are