BaMoO4 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.81 Å) and four longer (2.83 Å) Ba–O bond lengths. Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.81 Å. O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Mo6+ atom.