As we all know there is a symmetric and antisymmetric of 2 particles system states.
\begin{align} \text{symmetric} & \ \rightarrow & |μ,ν⟩=\frac{|μ⟩|ν⟩+|ν⟩|μ⟩}{\sqrt{2}} \\ \text{antisymmetric} & \ \rightarrow & |μ,ν⟩=\frac{|μ⟩|ν⟩-|ν⟩|μ⟩}{\sqrt{2}} \end{align}
Are there also other types of multi system with complex coefficients?
For example:
Two particles $|μ⟩$ and $|ν⟩$ s.t
$$
|μ,ν⟩=\frac{|μ⟩|ν⟩+i|ν⟩|μ⟩}{\sqrt{2}}
$$
This wave function keeps orthonormal to work out.
$$
⟨μ,ν|μ,ν⟩ = 1/2(⟨v|⟨μ|μ⟩|v⟩ + i⋅⟨v|⟨μ|ν⟩|μ⟩ + (i^*)⋅⟨μ|⟨ν|μ⟩|v⟩ + i⋅(i^*)⟨μ|⟨v|v⟩|μ⟩)
$$
The two middle components are equal to 0 as |μ⟩ orthogonal to |ν⟩.
So, we end up with
$$
⟨μ,ν|μ,ν⟩ = 1/2(⟨v|⟨μ|μ⟩|v⟩ + i⋅(i^*)⟨μ|⟨v|v⟩|μ⟩) = 1/2(1+i⋅(i^*)) = 1/2(1+1) = 1.
$$
The example I have shown is clearly neither a symmetrical nor anti-symmetrical case.