Li2NiSi4O10 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), one O(6), one O(8), and two equivalent O(5) atoms. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(7), one O(9), and two equivalent O(10) atoms. Ni(1) is bonded to one O(10), one O(8), one O(9), and two equivalent O(7) atoms to form NiO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 square pyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ni(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(1), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(1), and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Ni(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1), one Ni(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Li(2), one Ni(1), and one Si(4) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Ni(1), and one Si(3) atom.
Li2NiSi4O10 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), one O(6), one O(8), and two equivalent O(5) atoms. The Li(1)-O(1) bond length is 2.05 Å. The Li(1)-O(6) bond length is 2.02 Å. The Li(1)-O(8) bond length is 2.28 Å. There is one shorter (2.52 Å) and one longer (2.53 Å) Li(1)-O(5) bond length. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(7), one O(9), and two equivalent O(10) atoms. The Li(2)-O(7) bond length is 2.60 Å. The Li(2)-O(9) bond length is 1.96 Å. There is one shorter (2.11 Å) and one longer (2.18 Å) Li(2)-O(10) bond length. Ni(1) is bonded to one O(10), one O(8), one O(9), and two equivalent O(7) atoms to form NiO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 square pyramid. The Ni(1)-O(10) bond length is 2.10 Å. The Ni(1)-O(8) bond length is 2.04 Å. The Ni(1)-O(9) bond length is 2.02 Å. There is one shorter (2.04 Å) and one longer (2.09 Å) Ni(1)-O(7) bond length. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The Si(1)-O(1) bond length is 1.68 Å. The Si(1)-O(2) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.64 Å. The Si(1)-O(8) bond length is 1.59 Å. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ni(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The Si(2)-O(3) bond length is 1.64 Å. The Si(2)-O(4) bond length is 1.64 Å. The Si(2)-O(5) bond length is 1.65 Å. The Si(2)-O(7) bond length is 1.61 Å. In the third Si site, Si(3) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The Si(3)-O(10) bond length is 1.60 Å. The Si(3)-O(2) bond length is 1.63 Å. The Si(3)-O(5) bond length is 1.65 Å. The Si(3)-O(6) bond length is 1.67 Å. In the fourth Si site, Si(4) is bonded to one O(1), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The Si(4)-O(1) bond length is 1.65 Å. The Si(4)-O(3) bond length is 1.64 Å. The Si(4)-O(6) bond length is 1.67 Å. The Si(4)-O(9) bond length is 1.59 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Si(1), and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Ni(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1), one Ni(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Li(2), one Ni(1), and one Si(4) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Ni(1), and one Si(3) atom.