Crystal structure of the low temperature form of LiMn2O4 has been successfully determined by using single-crystal X-ray diffraction data at 130 K. It belongs to the orthorhombic system, space group Fddd with a = 24.750(3) Angstrom, b = 24.801(2) Angstrom, c = 8.1903(9) Angstrom, and v = 5027.4(9) Angstrom(3). The structure, including anisotropic displacement parameters for each atom, was refined to the conventional values R1 = 5.58%, wR2 = 7.16%, and S = 1.180 for 8082 independent reflections. The oxygen sublattice deformation toward the [1 1 0] direction in the low temperature form is clearly observed at 130 K. The structural phase transition around 280 and 320 K was precisely examined by differential scanning calorimetry (DSC) and single-crystal X-ray diffraction measurements using the single-crystal samples. (C) 2004 Elsevier B.V. All rights reserved.