The vanadium Magneli phases VnO(2n-1)
  To compare the metal-insulator transitions (MITs) of VO2 and V2O3 we analyze the relations between the structural and electronic properties of the vanadium Magneli phases. These materials set up the homologous series VnO(2n-1) (3 <= n <= 9) and have crystal structures comprising typical dioxide-like and sesquioxide-like regions. As the MITs of the vanadium Magneli phases are accompanied by structural transformations, we are able to discuss the effects of characteristic changes in the local atomic environments. The systematic investigation of the transport properties is based on a new and unifying description of the crystal structures of the Magneli phases including VO2 and V2O3. Our results lead to a comprehensive understanding of the MITs in the Magneli class and shed new light on the role of particular electronic states for the MIT of V2O3. 
Udo Schwingenschloegl and Volker Eyert