Na7MgCu3O8 crystallizes in the triclinic P1 space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(7), and one O(8) atom. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(7) atom. In the fifth Na site, Na(5) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(8) atom. In the sixth Na site, Na(6) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(6) atom. In the seventh Na site, Na(7) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. Mg(1) is bonded in a distorted tetrahedral geometry to one O(2), one O(4), one O(7), and one O(8) atom. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(5), one O(6), one O(7), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(6), one Na(7), and one Cu(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(6), one Na(7), one Mg(1), and one Cu(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(5), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Mg(1), one Cu(1), and one Cu(2) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(4), one Na(5), one Na(7), one Cu(2), and one Cu(3) atom to form a mixture of distorted corner and face-sharing ONa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 59°. In the sixth O site, O(6) is bonded to one Na(3), one Na(5), one Na(6), one Na(7), one Cu(2), and one Cu(3) atom to form a mixture of distorted corner and face-sharing ONa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 59°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(7), one Mg(1), and one Cu(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(7), one Mg(1), and one Cu(3) atom.
Na7MgCu3O8 crystallizes in the triclinic P1 space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), one O(3), and one O(7) atom. The Na(1)-O(1) bond length is 2.29 Å. The Na(1)-O(2) bond length is 2.90 Å. The Na(1)-O(3) bond length is 2.35 Å. The Na(1)-O(7) bond length is 2.32 Å. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(7), and one O(8) atom. The Na(2)-O(2) bond length is 2.68 Å. The Na(2)-O(3) bond length is 2.29 Å. The Na(2)-O(5) bond length is 2.25 Å. The Na(2)-O(7) bond length is 2.35 Å. The Na(2)-O(8) bond length is 2.63 Å. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(8) atom. The Na(3)-O(1) bond length is 2.34 Å. The Na(3)-O(3) bond length is 2.24 Å. The Na(3)-O(4) bond length is 2.45 Å. The Na(3)-O(6) bond length is 2.36 Å. The Na(3)-O(8) bond length is 2.75 Å. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(7) atom. The Na(4)-O(1) bond length is 2.37 Å. The Na(4)-O(2) bond length is 2.45 Å. The Na(4)-O(4) bond length is 2.31 Å. The Na(4)-O(5) bond length is 2.30 Å. The Na(4)-O(7) bond length is 2.66 Å. In the fifth Na site, Na(5) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(8) atom. The Na(5)-O(1) bond length is 2.56 Å. The Na(5)-O(3) bond length is 2.74 Å. The Na(5)-O(5) bond length is 2.30 Å. The Na(5)-O(6) bond length is 2.34 Å. The Na(5)-O(8) bond length is 2.35 Å. In the sixth Na site, Na(6) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(6) atom. The Na(6)-O(1) bond length is 2.24 Å. The Na(6)-O(2) bond length is 2.25 Å. The Na(6)-O(6) bond length is 2.24 Å. In the seventh Na site, Na(7) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. The Na(7)-O(1) bond length is 2.82 Å. The Na(7)-O(2) bond length is 2.40 Å. The Na(7)-O(5) bond length is 2.59 Å. The Na(7)-O(6) bond length is 2.53 Å. The Na(7)-O(7) bond length is 2.86 Å. The Na(7)-O(8) bond length is 2.33 Å. Mg(1) is bonded in a distorted tetrahedral geometry to one O(2), one O(4), one O(7), and one O(8) atom. The Mg(1)-O(2) bond length is 2.03 Å. The Mg(1)-O(4) bond length is 2.04 Å. The Mg(1)-O(7) bond length is 2.01 Å. The Mg(1)-O(8) bond length is 2.00 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Cu(1)-O(1) bond length is 1.93 Å. The Cu(1)-O(2) bond length is 1.96 Å. The Cu(1)-O(3) bond length is 1.98 Å. The Cu(1)-O(4) bond length is 2.16 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(3), one O(4), one O(5), and one O(6) atom. The Cu(2)-O(3) bond length is 1.85 Å. The Cu(2)-O(4) bond length is 1.91 Å. The Cu(2)-O(5) bond length is 1.87 Å. The Cu(2)-O(6) bond length is 1.89 Å. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(5), one O(6), one O(7), and one O(8) atom. The Cu(3)-O(5) bond length is 1.96 Å. The Cu(3)-O(6) bond length is 2.04 Å. The Cu(3)-O(7) bond length is 1.98 Å. The Cu(3)-O(8) bond length is 1.97 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(6), one Na(7), and one Cu(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(6), one Na(7), one Mg(1), and one Cu(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(5), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), one Na(4), one Mg(1), one Cu(1), and one Cu(2) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(4), one Na(5), one Na(7), one Cu(2), and one Cu(3) atom to form a mixture of distorted corner and face-sharing ONa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 59°. In the sixth O site, O(6) is bonded to one Na(3), one Na(5), one Na(6), one Na(7), one Cu(2), and one Cu(3) atom to form a mixture of distorted corner and face-sharing ONa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 59°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(7), one Mg(1), and one Cu(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(7), one Mg(1), and one Cu(3) atom.