Crystal structure of Au9In4(h) and Au7In3

The phase Au9In4(h) crystallizes in the Cu9Al4-type structure and Au7In3 has a hexagonal crystal structure with 60 atoms in the elementary cell. The structure is related to the γ-brass structure but with a different distribution of vacancies and another system of displacements. A spatial correlation of the core electrons with a very simple commensurability may be traced in the structure, together with a valence electron correlation which is geometrically related to the core electron correlation by a factor of 2. This energetically favourable binding relationship provides an argument in favour of the stability of Au7In3. (Auth.)