A new special class of Petrov type D vacuum space-times in dimension   five
  Using extensions of the Newman-Penrose and Geroch-Held-Penrose formalisms to five dimensions, we invariantly classify all Petrov type $D$ vacuum solutions for which the Riemann tensor is isotropic in a plane orthogonal to a pair of Weyl alligned null directions 
Alfonso Garc\'ia-Parrado G\'omez-Lobo and Lode Wylleman
gr-qc