LiNiP2O7 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(6), and two equivalent O(5) atoms. Ni(1) is bonded to one O(1), one O(6), one O(7), and two equivalent O(2) atoms to form NiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Ni(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(2) atom.
LiNiP2O7 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a rectangular see-saw-like geometry to one O(4), one O(6), and two equivalent O(5) atoms. The Li(1)-O(4) bond length is 1.96 Å. The Li(1)-O(6) bond length is 2.07 Å. There is one shorter (1.95 Å) and one longer (2.06 Å) Li(1)-O(5) bond length. Ni(1) is bonded to one O(1), one O(6), one O(7), and two equivalent O(2) atoms to form NiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. The Ni(1)-O(1) bond length is 2.03 Å. The Ni(1)-O(6) bond length is 2.06 Å. The Ni(1)-O(7) bond length is 1.99 Å. There is one shorter (2.06 Å) and one longer (2.08 Å) Ni(1)-O(2) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Ni(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.62 Å. The P(1)-O(5) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. The P(2)-O(3) bond length is 1.62 Å. The P(2)-O(4) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one P(2) atom.