LiNiPO4 crystallizes in the monoclinic Pc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ni(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form NiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Ni(1)O4 tetrahedra. In the second P site, P(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Ni(1)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent Ni(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Li(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Ni(2), and one P(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Ni(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), one Ni(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(2), and one P(1) atom.
LiNiPO4 crystallizes in the monoclinic Pc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ni(2)O4 tetrahedra. The Li(1)-O(1) bond length is 1.96 Å. The Li(1)-O(3) bond length is 2.00 Å. The Li(1)-O(5) bond length is 2.00 Å. The Li(1)-O(8) bond length is 2.00 Å. In the second Li site, Li(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. The Li(2)-O(2) bond length is 1.96 Å. The Li(2)-O(4) bond length is 1.99 Å. The Li(2)-O(6) bond length is 2.03 Å. The Li(2)-O(7) bond length is 2.02 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form NiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The Ni(1)-O(1) bond length is 1.97 Å. The Ni(1)-O(3) bond length is 1.99 Å. The Ni(1)-O(4) bond length is 2.00 Å. The Ni(1)-O(6) bond length is 1.94 Å. In the second Ni site, Ni(2) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The Ni(2)-O(2) bond length is 1.97 Å. The Ni(2)-O(5) bond length is 2.02 Å. The Ni(2)-O(7) bond length is 1.99 Å. The Ni(2)-O(8) bond length is 1.96 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Ni(1)O4 tetrahedra. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.56 Å. The P(1)-O(8) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Ni(1)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent Ni(2)O4 tetrahedra. The P(2)-O(2) bond length is 1.55 Å. The P(2)-O(5) bond length is 1.56 Å. The P(2)-O(6) bond length is 1.55 Å. The P(2)-O(7) bond length is 1.55 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Li(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Li(2), one Ni(2), and one P(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Ni(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Li(2), one Ni(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(2), and one P(1) atom.