Ho2Mo3O12 crystallizes in the tetragonal P-42_1m space group. Ho(1) is bonded to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted HoO7 hexagonal pyramids that share corners with two equivalent Mo(2)O4 tetrahedra, corners with five equivalent Mo(1)O4 tetrahedra, and  an edgeedge with one Ho(1)O7 hexagonal pyramid. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form MoO4 tetrahedra that share corners with five equivalent Ho(1)O7 hexagonal pyramids. In the second Mo site, Mo(2) is bonded to four equivalent O(2) atoms to form MoO4 tetrahedra that share corners with four equivalent Ho(1)O7 hexagonal pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Ho(1) and one Mo(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ho(1) and one Mo(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ho(1) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Ho(1) and one Mo(1) atom.
Ho2Mo3O12 crystallizes in the tetragonal P-42_1m space group. Ho(1) is bonded to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted HoO7 hexagonal pyramids that share corners with two equivalent Mo(2)O4 tetrahedra, corners with five equivalent Mo(1)O4 tetrahedra, and  an edgeedge with one Ho(1)O7 hexagonal pyramid. The Ho(1)-O(4) bond length is 2.28 Å. Both Ho(1)-O(1) bond lengths are 2.30 Å. Both Ho(1)-O(2) bond lengths are 2.22 Å. Both Ho(1)-O(3) bond lengths are 2.38 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form MoO4 tetrahedra that share corners with five equivalent Ho(1)O7 hexagonal pyramids. The Mo(1)-O(3) bond length is 1.80 Å. The Mo(1)-O(4) bond length is 1.75 Å. Both Mo(1)-O(1) bond lengths are 1.75 Å. In the second Mo site, Mo(2) is bonded to four equivalent O(2) atoms to form MoO4 tetrahedra that share corners with four equivalent Ho(1)O7 hexagonal pyramids. All Mo(2)-O(2) bond lengths are 1.76 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Ho(1) and one Mo(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ho(1) and one Mo(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ho(1) and one Mo(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Ho(1) and one Mo(1) atom.