Invariants for a Class of Nongeneric Three-qubit States
  We investigate the equivalence of quantum states under local unitary transformations. A complete set of invariants under local unitary transformations is presented for a class of non-generic three-qubit mixed states. It is shown that two such states in this class are locally equivalent if and only if all these invariants have equal values for them. 
Bao-Zhi Sun, Shao-Ming Fei