Sign of covalency in AlPdRe icosahedral quasicrystals obtained from atomic density and quasilattice constant

Atomic density and quasilattice constant of AlPdRe icosahedral quasicrystals decreases and slightly increases, respectively, with increasing concentration of transition metals, which have smaller atomic radii. Average atomic packing could not be described simply by rigid sphere packing, that is, the covalent nature of icosahedral clusters may form in metallic bonds.