The topology of the set of nonsoliton Lie algebras in the moduli space   of nilpotent Lie algebras
  A Lie algebra is called nonsoliton if it does not admit a soliton inner product. We demonstrate that the subset of nonsoliton Lie algebras in the moduli space of indecomposable n-dimensional N-graded nilpotent Lie algebras is discrete if and only if n <= 7. 
Tracy L. Payne
math.DG