MgHo6WO12 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(3), one O(8), and one O(9) atom. There are six inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(2), one O(5), one O(6), and one O(9) atom. In the second Ho site, Ho(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(5), one O(6), and one O(9) atom. In the third Ho site, Ho(3) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(2), one O(4), one O(6), and one O(7) atom. In the fourth Ho site, Ho(4) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(12), one O(3), one O(4), one O(5), and one O(8) atom. In the fifth Ho site, Ho(5) is bonded to one O(10), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form distorted HoO7 pentagonal bipyramids that share  a cornercorner with one W(1)O6 octahedra and  an edgeedge with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. In the sixth Ho site, Ho(6) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. W(1) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form WO6 octahedra that share  a cornercorner with one Ho(5)O7 pentagonal bipyramid and  an edgeedge with one Ho(5)O7 pentagonal bipyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Ho(1), one Ho(2), one Ho(3), and one Ho(4) atom. In the second O site, O(2) is bonded to one Ho(1), one Ho(3), one Ho(5), and one Ho(6) atom to form OHo4 tetrahedra that share  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(6)Ho4 tetrahedra, corners with two equivalent O(9)Ho3MgW trigonal bipyramids, corners with two equivalent O(3)Ho4Mg trigonal bipyramids,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(4)Ho4 tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra, and  an edgeedge with one O(6)Ho4 tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Ho(2), one Ho(4), one Ho(5), and one Ho(6) atom to form distorted OHo4Mg trigonal bipyramids that share  a cornercorner with one O(10)Ho3W tetrahedra,  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(5)Ho4 tetrahedra, corners with two equivalent O(2)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(4)Ho4 tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra,  an edgeedge with one O(6)Ho4 tetrahedra, and  an edgeedge with one O(9)Ho3MgW trigonal bipyramid. In the fourth O site, O(4) is bonded to one Ho(3), one Ho(4), one Ho(5), and one Ho(6) atom to form OHo4 tetrahedra that share  a cornercorner with one O(2)Ho4 tetrahedra, corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the fifth O site, O(5) is bonded to one Ho(1), one Ho(2), one Ho(4), and one Ho(6) atom to form OHo4 tetrahedra that share corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the sixth O site, O(6) is bonded to one Ho(1), one Ho(2), one Ho(3), and one Ho(5) atom to form distorted OHo4 tetrahedra that share  a cornercorner with one O(2)Ho4 tetrahedra, corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ho(3), one Ho(6), and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mg(1), one Ho(4), one Ho(5), and one W(1) atom. In the ninth O site, O(9) is bonded to one Mg(1), one Ho(1), one Ho(2), one Ho(5), and one W(1) atom to form distorted OHo3MgW trigonal bipyramids that share  a cornercorner with one O(10)Ho3W tetrahedra,  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(6)Ho4 tetrahedra, corners with two equivalent O(2)Ho4 tetrahedra,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra,  an edgeedge with one O(6)Ho4 tetrahedra, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the tenth O site, O(10) is bonded to one Ho(2), one Ho(5), one Ho(6), and one W(1) atom to form OHo3W tetrahedra that share corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(1), one Ho(2), one Ho(3), one Ho(4), and one W(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Ho(1), one Ho(4), one Ho(6), and one W(1) atom.
MgHo6WO12 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(3), one O(8), and one O(9) atom. The Mg(1)-O(1) bond length is 2.13 Å. The Mg(1)-O(11) bond length is 2.35 Å. The Mg(1)-O(3) bond length is 1.98 Å. The Mg(1)-O(8) bond length is 1.98 Å. The Mg(1)-O(9) bond length is 2.02 Å. There are six inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(2), one O(5), one O(6), and one O(9) atom. The Ho(1)-O(1) bond length is 2.23 Å. The Ho(1)-O(12) bond length is 2.25 Å. The Ho(1)-O(2) bond length is 2.17 Å. The Ho(1)-O(5) bond length is 2.27 Å. The Ho(1)-O(6) bond length is 2.47 Å. The Ho(1)-O(9) bond length is 2.41 Å. In the second Ho site, Ho(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(5), one O(6), and one O(9) atom. The Ho(2)-O(1) bond length is 2.52 Å. The Ho(2)-O(10) bond length is 2.20 Å. The Ho(2)-O(11) bond length is 2.43 Å. The Ho(2)-O(3) bond length is 2.37 Å. The Ho(2)-O(5) bond length is 2.17 Å. The Ho(2)-O(6) bond length is 2.44 Å. The Ho(2)-O(9) bond length is 2.40 Å. In the third Ho site, Ho(3) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(2), one O(4), one O(6), and one O(7) atom. The Ho(3)-O(1) bond length is 2.32 Å. The Ho(3)-O(11) bond length is 2.46 Å. The Ho(3)-O(2) bond length is 2.25 Å. The Ho(3)-O(4) bond length is 2.20 Å. The Ho(3)-O(6) bond length is 2.17 Å. The Ho(3)-O(7) bond length is 2.36 Å. In the fourth Ho site, Ho(4) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(12), one O(3), one O(4), one O(5), and one O(8) atom. The Ho(4)-O(1) bond length is 2.41 Å. The Ho(4)-O(11) bond length is 2.78 Å. The Ho(4)-O(12) bond length is 2.26 Å. The Ho(4)-O(3) bond length is 2.30 Å. The Ho(4)-O(4) bond length is 2.25 Å. The Ho(4)-O(5) bond length is 2.26 Å. The Ho(4)-O(8) bond length is 2.36 Å. In the fifth Ho site, Ho(5) is bonded to one O(10), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form distorted HoO7 pentagonal bipyramids that share  a cornercorner with one W(1)O6 octahedra and  an edgeedge with one W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. The Ho(5)-O(10) bond length is 2.41 Å. The Ho(5)-O(2) bond length is 2.23 Å. The Ho(5)-O(3) bond length is 2.43 Å. The Ho(5)-O(4) bond length is 2.29 Å. The Ho(5)-O(6) bond length is 2.26 Å. The Ho(5)-O(8) bond length is 2.33 Å. The Ho(5)-O(9) bond length is 2.52 Å. In the sixth Ho site, Ho(6) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. The Ho(6)-O(10) bond length is 2.29 Å. The Ho(6)-O(12) bond length is 2.70 Å. The Ho(6)-O(2) bond length is 2.29 Å. The Ho(6)-O(3) bond length is 2.59 Å. The Ho(6)-O(4) bond length is 2.20 Å. The Ho(6)-O(5) bond length is 2.29 Å. The Ho(6)-O(7) bond length is 2.28 Å. W(1) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form WO6 octahedra that share  a cornercorner with one Ho(5)O7 pentagonal bipyramid and  an edgeedge with one Ho(5)O7 pentagonal bipyramid. The W(1)-O(10) bond length is 2.13 Å. The W(1)-O(11) bond length is 2.03 Å. The W(1)-O(12) bond length is 2.10 Å. The W(1)-O(7) bond length is 2.08 Å. The W(1)-O(8) bond length is 2.12 Å. The W(1)-O(9) bond length is 2.26 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Ho(1), one Ho(2), one Ho(3), and one Ho(4) atom. In the second O site, O(2) is bonded to one Ho(1), one Ho(3), one Ho(5), and one Ho(6) atom to form OHo4 tetrahedra that share  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(6)Ho4 tetrahedra, corners with two equivalent O(9)Ho3MgW trigonal bipyramids, corners with two equivalent O(3)Ho4Mg trigonal bipyramids,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(4)Ho4 tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra, and  an edgeedge with one O(6)Ho4 tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Ho(2), one Ho(4), one Ho(5), and one Ho(6) atom to form distorted OHo4Mg trigonal bipyramids that share  a cornercorner with one O(10)Ho3W tetrahedra,  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(5)Ho4 tetrahedra, corners with two equivalent O(2)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(4)Ho4 tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra,  an edgeedge with one O(6)Ho4 tetrahedra, and  an edgeedge with one O(9)Ho3MgW trigonal bipyramid. In the fourth O site, O(4) is bonded to one Ho(3), one Ho(4), one Ho(5), and one Ho(6) atom to form OHo4 tetrahedra that share  a cornercorner with one O(2)Ho4 tetrahedra, corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the fifth O site, O(5) is bonded to one Ho(1), one Ho(2), one Ho(4), and one Ho(6) atom to form OHo4 tetrahedra that share corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the sixth O site, O(6) is bonded to one Ho(1), one Ho(2), one Ho(3), and one Ho(5) atom to form distorted OHo4 tetrahedra that share  a cornercorner with one O(2)Ho4 tetrahedra, corners with two equivalent O(10)Ho3W tetrahedra, corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ho(3), one Ho(6), and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mg(1), one Ho(4), one Ho(5), and one W(1) atom. In the ninth O site, O(9) is bonded to one Mg(1), one Ho(1), one Ho(2), one Ho(5), and one W(1) atom to form distorted OHo3MgW trigonal bipyramids that share  a cornercorner with one O(10)Ho3W tetrahedra,  a cornercorner with one O(4)Ho4 tetrahedra,  a cornercorner with one O(6)Ho4 tetrahedra, corners with two equivalent O(2)Ho4 tetrahedra,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(10)Ho3W tetrahedra,  an edgeedge with one O(5)Ho4 tetrahedra,  an edgeedge with one O(6)Ho4 tetrahedra, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the tenth O site, O(10) is bonded to one Ho(2), one Ho(5), one Ho(6), and one W(1) atom to form OHo3W tetrahedra that share corners with two equivalent O(4)Ho4 tetrahedra, corners with two equivalent O(5)Ho4 tetrahedra, corners with two equivalent O(6)Ho4 tetrahedra,  a cornercorner with one O(9)Ho3MgW trigonal bipyramid,  a cornercorner with one O(3)Ho4Mg trigonal bipyramid,  an edgeedge with one O(2)Ho4 tetrahedra,  an edgeedge with one O(9)Ho3MgW trigonal bipyramid, and  an edgeedge with one O(3)Ho4Mg trigonal bipyramid. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(1), one Ho(2), one Ho(3), one Ho(4), and one W(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Ho(1), one Ho(4), one Ho(6), and one W(1) atom.