We report on the temperature dependence of the phonons and crystallographic parameters in BiMnO 3 single crystals grown under high pressure and high temperature. The crystallographic structure of the sample was refined from room temperature to liquid helium temperature in the centrosymmetric C2/c space group, i.e., a group which does not allow ferroelectricity. In addition, the lattice dynamics was probed by Raman spectroscopy down to liquid nitrogen temperature, i.e., below the ferromagnetic

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... ansition at T C = 100 ± 2 K. Both crystallographic and Raman data indicate the absence of a structural phase transition at the ferromagnetic ordering or any other temperature. The Raman signature around T C shows a significant spin-phonon coupling for the high-frequency bands.