Twinning and structure of Eu(0.6)Sr(0.4)MnO3.

The crystal structure of europium strontium manganese trioxide, Eu(0.6)Sr(0.4)MnO3, has been refined using a multiply twinned single crystal containing six twin components. The MnO6 octahedra show Jahn-Teller distortions with nearly fourfold symmetry, but the octahedral tilting scheme reduces the crystal symmetry to orthorhombic (space group Pbnm). The refinement of site occupancies and the analysis of difference Fourier maps show that the Eu3+ and Sr2+ cations occupy different crystallographic positions with eightfold and twelvefold coordination, respectively.