Monoclinic La1−xBaxMnO3 (x = 0.185) at 160 K

Single‐crystal X‐ray diffraction has shown that lanthanum barium manganese trioxide, La_0.815Ba_0.185MnO₃, is monoclinic (I2/c) below a first‐order phase transition at 187.1 (3) K. This result differs from the Pbnm symmetry usually assigned to colossal magnetoresistance oxides, A_1−xA′_xMnO₃ with x≃ 0.2, which adopt a distorted perovskite‐type crystal structure. The Mn atom lies on an inversion center, the disordered Li/Ba site is on a twofold axis and one of the two independent O atoms also lies on a twofold axis.