The garnet-related oxide with nominal formula Li7La3Zr2O12 prepared by the sol-gel method is cubic, space group Ia-3d with lattice parameter a = 12.9720 angstrom at room temperature. The occupancies of three lithium positions (24d, 48g, 96h) and the position of a small amount of Al3+ (ca 0.61 wt%) inside the grains were determined by neutron diffraction. The occupancy of the 24d Li sites was reduced to 36.0% by the Al3+ occupying the 48g sites. The bulk and total Li+-ion conductivity at 25 degrees C was 3.1 x 10(-4) S cm(-1) and 1.4 x 10(-4) S cm(-1) with an activation energy 0.34 eV in the temperature range 25-160 degrees C. (C) 2012 Elsevier B.V. All rights reserved.