MgCo4(P2O7)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(13), one O(18), one O(6), one O(7), and one O(9) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-52°. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(14), one O(17), one O(2), one O(25), one O(26), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. In the second Co site, Co(2) is bonded to one O(1), one O(18), one O(24), one O(27), one O(28), and one O(4) atom to form CoO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. In the third Co site, Co(3) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(16), one O(19), one O(7), and one O(9) atom. In the fourth Co site, Co(4) is bonded to one O(11), one O(12), one O(20), one O(23), one O(5), and one O(6) atom to form CoO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and  a cornercorner with one P(6)O4 tetrahedra. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(13), one O(14), and one O(22) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the second P site, P(2) is bonded to one O(15), one O(23), one O(24), and one O(25) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and  a cornercorner with one P(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-52°. In the third P site, P(3) is bonded to one O(1), one O(19), one O(20), and one O(21) atom to form PO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and  a cornercorner with one P(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-50°. In the fourth P site, P(4) is bonded to one O(18), one O(22), one O(26), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-51°. In the fifth P site, P(5) is bonded to one O(27), one O(5), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-42°. In the sixth P site, P(6) is bonded to one O(11), one O(15), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-42°. In the seventh P site, P(7) is bonded to one O(16), one O(17), one O(28), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, and  a cornercorner with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the eighth P site, P(8) is bonded to one O(10), one O(2), one O(21), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-48°. There are twenty-eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Co(1) and one P(8) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(8) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Co(4) and one P(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Co(4), and one P(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Co(3), and one P(5) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one P(5) and one P(7) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Mg(1), one Co(3), and one P(6) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Co(3) and one P(8) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Co(4) and one P(6) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Co(4) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Mg(1), one Co(3), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(1) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(2) and one P(6) atom. In the sixteenth O site, O(16) is bonded in a bent 120 degrees geometry to one Co(3) and one P(7) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(7) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(2), and one P(4) atom. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Co(3) and one P(3) atom. In the twentieth O site, O(20) is bonded in a bent 120 degrees geometry to one Co(4) and one P(3) atom. In the twenty-first O site, O(21) is bonded in a bent 120 degrees geometry to one P(3) and one P(8) atom. In the twenty-second O site, O(22) is bonded in a bent 120 degrees geometry to one P(1) and one P(4) atom. In the twenty-third O site, O(23) is bonded in a distorted bent 150 degrees geometry to one Co(4) and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(2) atom. In the twenty-fifth O site, O(25) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the twenty-sixth O site, O(26) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(4) atom. In the twenty-seventh O site, O(27) is bonded in a bent 150 degrees geometry to one Co(2) and one P(5) atom. In the twenty-eighth O site, O(28) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(7) atom.
MgCo4(P2O7)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(13), one O(18), one O(6), one O(7), and one O(9) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra, and  an edgeedge with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-52°. The Mg(1)-O(13) bond length is 1.98 Å. The Mg(1)-O(18) bond length is 2.02 Å. The Mg(1)-O(6) bond length is 2.36 Å. The Mg(1)-O(7) bond length is 2.07 Å. The Mg(1)-O(9) bond length is 2.09 Å. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(14), one O(17), one O(2), one O(25), one O(26), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. The Co(1)-O(14) bond length is 1.92 Å. The Co(1)-O(17) bond length is 2.06 Å. The Co(1)-O(2) bond length is 1.88 Å. The Co(1)-O(25) bond length is 2.15 Å. The Co(1)-O(26) bond length is 1.99 Å. The Co(1)-O(3) bond length is 2.05 Å. In the second Co site, Co(2) is bonded to one O(1), one O(18), one O(24), one O(27), one O(28), and one O(4) atom to form CoO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. The Co(2)-O(1) bond length is 1.99 Å. The Co(2)-O(18) bond length is 2.08 Å. The Co(2)-O(24) bond length is 1.97 Å. The Co(2)-O(27) bond length is 2.12 Å. The Co(2)-O(28) bond length is 1.90 Å. The Co(2)-O(4) bond length is 1.98 Å. In the third Co site, Co(3) is bonded in a 6-coordinate geometry to one O(10), one O(13), one O(16), one O(19), one O(7), and one O(9) atom. The Co(3)-O(10) bond length is 1.90 Å. The Co(3)-O(13) bond length is 2.56 Å. The Co(3)-O(16) bond length is 1.87 Å. The Co(3)-O(19) bond length is 1.95 Å. The Co(3)-O(7) bond length is 2.10 Å. The Co(3)-O(9) bond length is 2.06 Å. In the fourth Co site, Co(4) is bonded to one O(11), one O(12), one O(20), one O(23), one O(5), and one O(6) atom to form CoO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and  a cornercorner with one P(6)O4 tetrahedra. The Co(4)-O(11) bond length is 1.95 Å. The Co(4)-O(12) bond length is 1.94 Å. The Co(4)-O(20) bond length is 1.94 Å. The Co(4)-O(23) bond length is 2.05 Å. The Co(4)-O(5) bond length is 2.02 Å. The Co(4)-O(6) bond length is 2.07 Å. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(13), one O(14), and one O(22) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-51°. The P(1)-O(12) bond length is 1.54 Å. The P(1)-O(13) bond length is 1.53 Å. The P(1)-O(14) bond length is 1.53 Å. The P(1)-O(22) bond length is 1.61 Å. In the second P site, P(2) is bonded to one O(15), one O(23), one O(24), and one O(25) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and  a cornercorner with one P(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-52°. The P(2)-O(15) bond length is 1.61 Å. The P(2)-O(23) bond length is 1.54 Å. The P(2)-O(24) bond length is 1.52 Å. The P(2)-O(25) bond length is 1.54 Å. In the third P site, P(3) is bonded to one O(1), one O(19), one O(20), and one O(21) atom to form PO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, and  a cornercorner with one P(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-50°. The P(3)-O(1) bond length is 1.53 Å. The P(3)-O(19) bond length is 1.54 Å. The P(3)-O(20) bond length is 1.52 Å. The P(3)-O(21) bond length is 1.62 Å. In the fourth P site, P(4) is bonded to one O(18), one O(22), one O(26), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-51°. The P(4)-O(18) bond length is 1.56 Å. The P(4)-O(22) bond length is 1.62 Å. The P(4)-O(26) bond length is 1.51 Å. The P(4)-O(6) bond length is 1.53 Å. In the fifth P site, P(5) is bonded to one O(27), one O(5), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-42°. The P(5)-O(27) bond length is 1.52 Å. The P(5)-O(5) bond length is 1.52 Å. The P(5)-O(7) bond length is 1.56 Å. The P(5)-O(8) bond length is 1.62 Å. In the sixth P site, P(6) is bonded to one O(11), one O(15), one O(3), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-42°. The P(6)-O(11) bond length is 1.54 Å. The P(6)-O(15) bond length is 1.62 Å. The P(6)-O(3) bond length is 1.51 Å. The P(6)-O(9) bond length is 1.57 Å. In the seventh P site, P(7) is bonded to one O(16), one O(17), one O(28), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, and  a cornercorner with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-48°. The P(7)-O(16) bond length is 1.55 Å. The P(7)-O(17) bond length is 1.50 Å. The P(7)-O(28) bond length is 1.56 Å. The P(7)-O(8) bond length is 1.63 Å. In the eighth P site, P(8) is bonded to one O(10), one O(2), one O(21), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-48°. The P(8)-O(10) bond length is 1.53 Å. The P(8)-O(2) bond length is 1.53 Å. The P(8)-O(21) bond length is 1.62 Å. The P(8)-O(4) bond length is 1.54 Å. There are twenty-eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Co(1) and one P(8) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(8) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Co(4) and one P(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one Co(4), and one P(4) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Co(3), and one P(5) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one P(5) and one P(7) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Mg(1), one Co(3), and one P(6) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Co(3) and one P(8) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Co(4) and one P(6) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Co(4) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Mg(1), one Co(3), and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(1) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(2) and one P(6) atom. In the sixteenth O site, O(16) is bonded in a bent 120 degrees geometry to one Co(3) and one P(7) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(7) atom. In the eighteenth O site, O(18) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(2), and one P(4) atom. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Co(3) and one P(3) atom. In the twentieth O site, O(20) is bonded in a bent 120 degrees geometry to one Co(4) and one P(3) atom. In the twenty-first O site, O(21) is bonded in a bent 120 degrees geometry to one P(3) and one P(8) atom. In the twenty-second O site, O(22) is bonded in a bent 120 degrees geometry to one P(1) and one P(4) atom. In the twenty-third O site, O(23) is bonded in a distorted bent 150 degrees geometry to one Co(4) and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(2) atom. In the twenty-fifth O site, O(25) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the twenty-sixth O site, O(26) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(4) atom. In the twenty-seventh O site, O(27) is bonded in a bent 150 degrees geometry to one Co(2) and one P(5) atom. In the twenty-eighth O site, O(28) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(7) atom.