LiNiPO4 crystallizes in the trigonal P31c space group. Li(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with three equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form NiO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and edges with two equivalent Ni(1)O5 trigonal bipyramids. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with six equivalent Li(1)O4 tetrahedra and corners with three equivalent Ni(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(4) and three equivalent O(3) atoms to form PO4 tetrahedra that share corners with three equivalent Li(1)O4 tetrahedra and corners with six equivalent Ni(1)O5 trigonal bipyramids. In the third P site, P(3) is bonded to one O(6) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Li(1)O4 tetrahedra and corners with six equivalent Ni(1)O5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ni(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a tetrahedral geometry to three equivalent Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ni(1) and one P(3) atom.
LiNiPO4 crystallizes in the trigonal P31c space group. Li(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with three equivalent Ni(1)O5 trigonal bipyramids. The Li(1)-O(1) bond length is 1.93 Å. The Li(1)-O(2) bond length is 2.02 Å. The Li(1)-O(3) bond length is 2.03 Å. The Li(1)-O(5) bond length is 1.94 Å. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form NiO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and edges with two equivalent Ni(1)O5 trigonal bipyramids. The Ni(1)-O(1) bond length is 1.98 Å. The Ni(1)-O(2) bond length is 1.99 Å. The Ni(1)-O(3) bond length is 2.05 Å. The Ni(1)-O(4) bond length is 2.19 Å. The Ni(1)-O(6) bond length is 2.18 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(5) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with six equivalent Li(1)O4 tetrahedra and corners with three equivalent Ni(1)O5 trigonal bipyramids. The P(1)-O(5) bond length is 1.54 Å. All P(1)-O(1) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to one O(4) and three equivalent O(3) atoms to form PO4 tetrahedra that share corners with three equivalent Li(1)O4 tetrahedra and corners with six equivalent Ni(1)O5 trigonal bipyramids. The P(2)-O(4) bond length is 1.62 Å. All P(2)-O(3) bond lengths are 1.54 Å. In the third P site, P(3) is bonded to one O(6) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Li(1)O4 tetrahedra and corners with six equivalent Ni(1)O5 trigonal bipyramids. The P(3)-O(6) bond length is 1.60 Å. All P(3)-O(2) bond lengths are 1.54 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ni(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a tetrahedral geometry to three equivalent Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ni(1) and one P(3) atom.