Copper cyanide forms a complex coordination compound, when dissolved in a solution containing excess ($\ce{CN^-}$) ions.
My question is whether it forms $\ce{[Cu(CN)_4]^{3-}}$ only or both $\ce{[Cu(CN)_3]^{2-}}$ and $\ce{[Cu(CN)_4]^{3-}}$ complexes?
Wikipedia says that both complexes are formed, but I am not sure if its a reliable source.