Na4Mg(MoO4)2 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one Mg(1), one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one Mg(1), one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to two equivalent Na(1), two equivalent Na(2), two equivalent O(2), and two equivalent O(3) atoms to form distorted MgNa4O4 tetrahedra that share corners with four equivalent Mo(1)O4 tetrahedra. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form MoO4 tetrahedra that share corners with four equivalent Mg(1)Na4O4 tetrahedra. In the second Mo site, Mo(2) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Mo(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Mg(1), and one Mo(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Mg(1), and one Mo(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one Mo(2) atom.
Na4Mg(MoO4)2 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one Mg(1), one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Na(1)-Mg(1) bond length is 2.32 Å. The Na(1)-O(1) bond length is 2.31 Å. The Na(1)-O(2) bond length is 2.52 Å. Both Na(1)-O(3) bond lengths are 2.51 Å. Both Na(1)-O(4) bond lengths are 2.31 Å. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one Mg(1), one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. The Na(2)-Mg(1) bond length is 2.33 Å. The Na(2)-O(3) bond length is 2.51 Å. The Na(2)-O(4) bond length is 2.31 Å. Both Na(2)-O(1) bond lengths are 2.30 Å. Both Na(2)-O(2) bond lengths are 2.52 Å. Mg(1) is bonded to two equivalent Na(1), two equivalent Na(2), two equivalent O(2), and two equivalent O(3) atoms to form distorted MgNa4O4 tetrahedra that share corners with four equivalent Mo(1)O4 tetrahedra. Both Mg(1)-O(2) bond lengths are 2.00 Å. Both Mg(1)-O(3) bond lengths are 2.01 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form MoO4 tetrahedra that share corners with four equivalent Mg(1)Na4O4 tetrahedra. Both Mo(1)-O(2) bond lengths are 2.02 Å. Both Mo(1)-O(3) bond lengths are 2.02 Å. In the second Mo site, Mo(2) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Mo(2)-O(1) bond lengths are 1.80 Å. Both Mo(2)-O(4) bond lengths are 1.80 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Mo(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Mg(1), and one Mo(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Mg(1), and one Mo(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one Mo(2) atom.