LiNiPO4 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Ni(1)O5 trigonal bipyramid, corners with two equivalent Li(1)O5 trigonal bipyramids,  an edgeedge with one P(1)O4 tetrahedra,  an edgeedge with one Li(1)O5 trigonal bipyramid, and edges with two equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted NiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid,  an edgeedge with one P(1)O4 tetrahedra,  an edgeedge with one Ni(1)O5 trigonal bipyramid, and edges with two equivalent Li(1)O5 trigonal bipyramids. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Li(1)O5 trigonal bipyramids, corners with three equivalent Ni(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Li(1), one Ni(1), and one P(1) atom. In the second O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1), one Ni(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Ni(1), and one P(1) atom.
LiNiPO4 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Ni(1)O5 trigonal bipyramid, corners with two equivalent Li(1)O5 trigonal bipyramids,  an edgeedge with one P(1)O4 tetrahedra,  an edgeedge with one Li(1)O5 trigonal bipyramid, and edges with two equivalent Ni(1)O5 trigonal bipyramids. The Li(1)-O(2) bond length is 2.16 Å. There is one shorter (1.94 Å) and one longer (2.10 Å) Li(1)-O(1) bond length. There is one shorter (2.13 Å) and one longer (2.37 Å) Li(1)-O(3) bond length. Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted NiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid,  an edgeedge with one P(1)O4 tetrahedra,  an edgeedge with one Ni(1)O5 trigonal bipyramid, and edges with two equivalent Li(1)O5 trigonal bipyramids. The Ni(1)-O(1) bond length is 2.11 Å. The Ni(1)-O(2) bond length is 2.00 Å. The Ni(1)-O(3) bond length is 1.98 Å. There is one shorter (1.98 Å) and one longer (2.13 Å) Ni(1)-O(4) bond length. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Li(1)O5 trigonal bipyramids, corners with three equivalent Ni(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.56 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Li(1), one Ni(1), and one P(1) atom. In the second O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1), one Ni(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Ni(1), and one P(1) atom.