Na4Mg(Mo2O5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), one O(7), and one O(9) atom. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MoO6 octahedra that share corners with four equivalent Mo(2)O6 octahedra and  a cornercorner with one Mo(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 5-16°. In the second Mo site, Mo(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form MoO6 octahedra that share corners with four equivalent Mo(1)O6 octahedra and  a cornercorner with one Mo(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 5-16°. In the third Mo site, Mo(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form distorted corner-sharing MoO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 36°. In the fourth Mo site, Mo(4) is bonded in a 3-coordinate geometry to one O(6), one O(7), and one O(9) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(4)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(4)Na4Mo2 octahedra, faces with two equivalent O(2)Na4Mo2 octahedra, and faces with two equivalent O(3)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(3)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(3)Na4Mo2 octahedra, faces with two equivalent O(1)Na4Mo2 octahedra, and faces with two equivalent O(4)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(2)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(2)Na4Mo2 octahedra, faces with two equivalent O(1)Na4Mo2 octahedra, and faces with two equivalent O(4)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(1)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(1)Na4Mo2 octahedra, faces with two equivalent O(2)Na4Mo2 octahedra, and faces with two equivalent O(3)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Mo(1), and one Mo(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(2), one Na(4), one Mg(1), one Mo(1), and one Mo(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Mg(1), one Mo(2), and one Mo(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one Mo(2), and one Mo(3) atom. In the ninth O site, O(9) is bonded to one Na(1), one Na(4), one Mg(1), one Mo(3), and one Mo(4) atom to form distorted corner-sharing ONa2MgMo2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 35-83°. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Mg(1), and one Mo(3) atom.
Na4Mg(Mo2O5)2 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(9) atom. The Na(1)-O(1) bond length is 2.38 Å. The Na(1)-O(2) bond length is 2.48 Å. The Na(1)-O(3) bond length is 2.46 Å. The Na(1)-O(4) bond length is 2.52 Å. The Na(1)-O(5) bond length is 2.66 Å. The Na(1)-O(7) bond length is 2.79 Å. The Na(1)-O(9) bond length is 2.55 Å. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. The Na(2)-O(1) bond length is 2.64 Å. The Na(2)-O(10) bond length is 2.46 Å. The Na(2)-O(2) bond length is 2.52 Å. The Na(2)-O(3) bond length is 2.66 Å. The Na(2)-O(4) bond length is 2.47 Å. The Na(2)-O(6) bond length is 2.60 Å. The Na(2)-O(8) bond length is 2.70 Å. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and one O(7) atom. The Na(3)-O(1) bond length is 2.48 Å. The Na(3)-O(10) bond length is 2.45 Å. The Na(3)-O(2) bond length is 2.65 Å. The Na(3)-O(3) bond length is 2.54 Å. The Na(3)-O(4) bond length is 2.67 Å. The Na(3)-O(5) bond length is 2.71 Å. The Na(3)-O(7) bond length is 2.63 Å. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. The Na(4)-O(1) bond length is 2.48 Å. The Na(4)-O(2) bond length is 2.45 Å. The Na(4)-O(3) bond length is 2.47 Å. The Na(4)-O(4) bond length is 2.37 Å. The Na(4)-O(6) bond length is 2.80 Å. The Na(4)-O(8) bond length is 2.67 Å. The Na(4)-O(9) bond length is 2.55 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), one O(7), and one O(9) atom. The Mg(1)-O(10) bond length is 2.00 Å. The Mg(1)-O(6) bond length is 2.09 Å. The Mg(1)-O(7) bond length is 2.10 Å. The Mg(1)-O(9) bond length is 1.92 Å. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MoO6 octahedra that share corners with four equivalent Mo(2)O6 octahedra and  a cornercorner with one Mo(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 5-16°. The Mo(1)-O(1) bond length is 2.05 Å. The Mo(1)-O(2) bond length is 2.04 Å. The Mo(1)-O(3) bond length is 2.04 Å. The Mo(1)-O(4) bond length is 2.04 Å. The Mo(1)-O(5) bond length is 2.18 Å. The Mo(1)-O(6) bond length is 2.22 Å. In the second Mo site, Mo(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form MoO6 octahedra that share corners with four equivalent Mo(1)O6 octahedra and  a cornercorner with one Mo(3)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 5-16°. The Mo(2)-O(1) bond length is 2.15 Å. The Mo(2)-O(2) bond length is 2.15 Å. The Mo(2)-O(3) bond length is 2.15 Å. The Mo(2)-O(4) bond length is 2.15 Å. The Mo(2)-O(7) bond length is 2.22 Å. The Mo(2)-O(8) bond length is 2.18 Å. In the third Mo site, Mo(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form distorted corner-sharing MoO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 36°. The Mo(3)-O(10) bond length is 1.96 Å. The Mo(3)-O(5) bond length is 1.84 Å. The Mo(3)-O(8) bond length is 1.83 Å. The Mo(3)-O(9) bond length is 2.48 Å. In the fourth Mo site, Mo(4) is bonded in a 3-coordinate geometry to one O(6), one O(7), and one O(9) atom. The Mo(4)-O(6) bond length is 1.98 Å. The Mo(4)-O(7) bond length is 1.97 Å. The Mo(4)-O(9) bond length is 1.94 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(4)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(4)Na4Mo2 octahedra, faces with two equivalent O(2)Na4Mo2 octahedra, and faces with two equivalent O(3)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(3)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(3)Na4Mo2 octahedra, faces with two equivalent O(1)Na4Mo2 octahedra, and faces with two equivalent O(4)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(2)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(2)Na4Mo2 octahedra, faces with two equivalent O(1)Na4Mo2 octahedra, and faces with two equivalent O(4)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Mo(1), and one Mo(2) atom to form distorted ONa4Mo2 octahedra that share corners with two equivalent O(1)Na4Mo2 octahedra, corners with two equivalent O(9)Na2MgMo2 trigonal bipyramids, edges with two equivalent O(1)Na4Mo2 octahedra, faces with two equivalent O(2)Na4Mo2 octahedra, and faces with two equivalent O(3)Na4Mo2 octahedra. The corner-sharing octahedral tilt angles range from 2-4°. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Mo(1), and one Mo(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Na(2), one Na(4), one Mg(1), one Mo(1), and one Mo(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Mg(1), one Mo(2), and one Mo(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(2), one Na(4), one Mo(2), and one Mo(3) atom. In the ninth O site, O(9) is bonded to one Na(1), one Na(4), one Mg(1), one Mo(3), and one Mo(4) atom to form distorted corner-sharing ONa2MgMo2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 35-83°. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Mg(1), and one Mo(3) atom.