  It is known that the dimension of the Schur multiplier of a non-abelian
nilpotent Lie algebra $L$ of dimension $n$ is equal to
$\frac{1}{2}(n-1)(n-2)+1-s(L)$ for some $ s(L)\geq0 $. The structure of all
nilpotent Lie algebras has been given for $ s(L) \leq 4 $ in several papers.
Here, we are going to give the structure of all non-abelian nilpotent Lie
algebras for $s(L)=5$.
