Indirect Mn-Mn pair interaction induces pseudogap in density of states   of Al(Si)-Mn approximants
  The effect on the electronic structure of an indirect Mn-Mn interaction mediated by the valence states and the sp-d hybridisation is presented. In Al(rich)-Mn phases related to quasicrystals (Al12Mn, o-Al6Mn, alpha-Al9Mn2Si), this indirect interaction creates a Hume-Rothery pseudogap in the density of states together with a minimisation of the band energy. It is shown that Mn-Mn interaction up to distances around 1.0-2.0 nm plays an essential role in stabilizing related quasicrystal structures. 
G. Trambly de Laissardi\`ere, D. Nguyen-Manh, D. Mayou