Ab Initio Structure Determination of Li₂MnO₃ from X-ray Powder Diffraction Data

The results of the structural determination of Li₂MnO₃ from X-ray powder diffraction data and the refinement by the Rietveld technique are presented. The Li₂MnO₃ structure has a monoclinic cell with space group C2/m(Z = 4) and cell parameters a = 4.9246 (1), b = 8.5216 (1), c = 5.0245 (1) Å, β = 109.398 (1)°; the refinement with 14 structural parameters for 165 reflections in the pattern leads to R_wp = 17.61%, R_p = 13.25%, R_B = 7.07% and S = 3.52. Such a solution agrees with a single-crystal structure determination previously reported in the literature and allows other hypotheses to be rejected.