Li2Fe2Ni(PO4)3 crystallizes in the monoclinic C2 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to two equivalent O(11), two equivalent O(5), and two equivalent O(8) atoms. In the third Li site, Li(3) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), one O(8), and one O(9) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(12), one O(5), one O(8), and one O(9) atom. Ni(1) is bonded to one O(11), one O(12), one O(3), one O(6), one O(7), and one O(8) atom to form distorted NiO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(5), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-49°. In the second P site, P(2) is bonded to two equivalent O(10) and two equivalent O(7) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-51°. In the third P site, P(3) is bonded to two equivalent O(2) and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. In the fourth P site, P(4) is bonded to one O(1), one O(11), one O(12), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-39°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one P(4) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Ni(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Fe(1), one Ni(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Li(2), one Li(3), one Fe(2), one Ni(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Li(2), one Li(3), one Fe(2), one Ni(1), and one P(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(3), one Fe(2), one Ni(1), and one P(4) atom.
Li2Fe2Ni(PO4)3 crystallizes in the monoclinic C2 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. Both Li(1)-O(3) bond lengths are 2.54 Å. Both Li(1)-O(4) bond lengths are 2.14 Å. Both Li(1)-O(7) bond lengths are 2.09 Å. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to two equivalent O(11), two equivalent O(5), and two equivalent O(8) atoms. Both Li(2)-O(11) bond lengths are 2.58 Å. Both Li(2)-O(5) bond lengths are 2.22 Å. Both Li(2)-O(8) bond lengths are 2.13 Å. In the third Li site, Li(3) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), one O(8), and one O(9) atom. The Li(3)-O(10) bond length is 2.25 Å. The Li(3)-O(11) bond length is 2.16 Å. The Li(3)-O(12) bond length is 2.12 Å. The Li(3)-O(8) bond length is 2.60 Å. The Li(3)-O(9) bond length is 2.24 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. The Fe(1)-O(1) bond length is 1.93 Å. The Fe(1)-O(2) bond length is 1.94 Å. The Fe(1)-O(3) bond length is 2.08 Å. The Fe(1)-O(4) bond length is 2.04 Å. The Fe(1)-O(6) bond length is 2.05 Å. The Fe(1)-O(7) bond length is 2.07 Å. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(12), one O(5), one O(8), and one O(9) atom. The Fe(2)-O(10) bond length is 2.04 Å. The Fe(2)-O(11) bond length is 2.24 Å. The Fe(2)-O(12) bond length is 2.24 Å. The Fe(2)-O(5) bond length is 2.05 Å. The Fe(2)-O(8) bond length is 2.23 Å. The Fe(2)-O(9) bond length is 2.03 Å. Ni(1) is bonded to one O(11), one O(12), one O(3), one O(6), one O(7), and one O(8) atom to form distorted NiO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  a faceface with one Fe(1)O6 octahedra. The Ni(1)-O(11) bond length is 2.18 Å. The Ni(1)-O(12) bond length is 2.16 Å. The Ni(1)-O(3) bond length is 2.16 Å. The Ni(1)-O(6) bond length is 2.09 Å. The Ni(1)-O(7) bond length is 2.17 Å. The Ni(1)-O(8) bond length is 2.15 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(5), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-49°. The P(1)-O(3) bond length is 1.58 Å. The P(1)-O(5) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.57 Å. The P(1)-O(9) bond length is 1.53 Å. In the second P site, P(2) is bonded to two equivalent O(10) and two equivalent O(7) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-51°. Both P(2)-O(10) bond lengths are 1.52 Å. Both P(2)-O(7) bond lengths are 1.58 Å. In the third P site, P(3) is bonded to two equivalent O(2) and two equivalent O(8) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. Both P(3)-O(2) bond lengths are 1.52 Å. Both P(3)-O(8) bond lengths are 1.57 Å. In the fourth P site, P(4) is bonded to one O(1), one O(11), one O(12), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-39°. The P(4)-O(1) bond length is 1.52 Å. The P(4)-O(11) bond length is 1.57 Å. The P(4)-O(12) bond length is 1.57 Å. The P(4)-O(4) bond length is 1.54 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one P(4) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(1), one Ni(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Fe(1), one Ni(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Li(2), one Li(3), one Fe(2), one Ni(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(3), one Fe(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Li(2), one Li(3), one Fe(2), one Ni(1), and one P(4) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Li(3), one Fe(2), one Ni(1), and one P(4) atom.