Li2NiSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic Pnma space group. Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Ni(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. Ni(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form NiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and corners with eight equivalent Li(1)O4 tetrahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Ni(1)O4 tetrahedra and corners with eight equivalent Li(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra. In the third O site, O(3) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra.
Li2NiSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic Pnma space group. Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Ni(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The Li(1)-O(2) bond length is 1.93 Å. The Li(1)-O(3) bond length is 1.96 Å. There is one shorter (1.96 Å) and one longer (2.01 Å) Li(1)-O(1) bond length. Ni(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form NiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra and corners with eight equivalent Li(1)O4 tetrahedra. The Ni(1)-O(2) bond length is 1.99 Å. The Ni(1)-O(3) bond length is 2.01 Å. Both Ni(1)-O(1) bond lengths are 1.99 Å. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Ni(1)O4 tetrahedra and corners with eight equivalent Li(1)O4 tetrahedra. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.66 Å. Both Si(1)-O(1) bond lengths are 1.66 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra. In the third O site, O(3) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra.