MgCoP2O7 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with three equivalent Co(1)O6 octahedra. Co(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with three equivalent Mg(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-62°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-62°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Co(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Co(1), and one P(1) atom.
MgCoP2O7 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MgO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with three equivalent Co(1)O6 octahedra. The Mg(1)-O(2) bond length is 2.07 Å. The Mg(1)-O(3) bond length is 2.08 Å. The Mg(1)-O(4) bond length is 2.24 Å. The Mg(1)-O(5) bond length is 2.06 Å. The Mg(1)-O(6) bond length is 2.28 Å. The Mg(1)-O(7) bond length is 2.07 Å. Co(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with three equivalent Mg(1)O6 octahedra. The Co(1)-O(2) bond length is 2.09 Å. The Co(1)-O(3) bond length is 2.10 Å. The Co(1)-O(4) bond length is 2.10 Å. The Co(1)-O(5) bond length is 2.32 Å. The Co(1)-O(6) bond length is 2.06 Å. The Co(1)-O(7) bond length is 2.29 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-62°. The P(1)-O(1) bond length is 1.59 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(7) bond length is 1.53 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-62°. The P(2)-O(1) bond length is 1.58 Å. The P(2)-O(3) bond length is 1.54 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Co(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Mg(1), one Co(1), and one P(1) atom.