The Crystal Structure of MnF3 Revisited

We correct the crystal structure of MnF ₃, of which the space group was reported as monoclinic C2/c (no. 15) with a = 8.9202, b = 5.0472, c = 13.4748 Å, β = 92.64°, V = 606.02 ų, Z = 12, mS48, T not given, likely 298 K. In the structure model proposed here, we use a unit cell of one third of the former volume. The ruby red crystals of MnF ₃ were synthesized by a high-pressure/high-temperature method, where MnF ₄ was used as a starting material. As determined on a single crystal, MnF ₃ crystallizes in the monoclinic space group I2/a (no. 15) with a = 5.4964(11), b = 5.0084(10), c = 7.2411(14) Å, β = 93.00(3)°, V = 199.06(7) Å ³, Z = 4, mS16, T = 183(2) K. The crystal structure of MnF ₃ is related by a direct group-subgroup transition to the VF ₃ structure-type. We performed quantum chemical calculations on the crystal structure to allow the assignment of bands of the obtained vibrational spectra.