Li4Si3(NiO5)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with three equivalent Ni(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded in a distorted pentagonal planar geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(5) atoms to form NiO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and corners with four equivalent Ni(1)O5 trigonal bipyramids. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Ni(1), and one Si(2) atom to form distorted OLi2SiNi trigonal pyramids that share  a cornercorner with one O(3)Li2SiNi tetrahedra,  a cornercorner with one O(2)Li2SiNi trigonal pyramid, corners with two equivalent O(5)LiSiNi2 trigonal pyramids, corners with three equivalent O(1)Li2SiNi trigonal pyramids, and  an edgeedge with one O(3)Li2SiNi tetrahedra. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form distorted OLi2SiNi trigonal pyramids that share corners with four equivalent O(3)Li2SiNi tetrahedra,  a cornercorner with one O(1)Li2SiNi trigonal pyramid, corners with three equivalent O(5)LiSiNi2 trigonal pyramids,  an edgeedge with one O(2)Li2SiNi trigonal pyramid, and  an edgeedge with one O(5)LiSiNi2 trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Ni(1), and one Si(1) atom to form distorted OLi2SiNi tetrahedra that share  a cornercorner with one O(1)Li2SiNi trigonal pyramid, corners with four equivalent O(2)Li2SiNi trigonal pyramids, corners with four equivalent O(5)LiSiNi2 trigonal pyramids, and  an edgeedge with one O(1)Li2SiNi trigonal pyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded to one Li(1), two equivalent Ni(1), and one Si(1) atom to form distorted OLiSiNi2 trigonal pyramids that share corners with four equivalent O(3)Li2SiNi tetrahedra, corners with two equivalent O(1)Li2SiNi trigonal pyramids, corners with three equivalent O(2)Li2SiNi trigonal pyramids,  an edgeedge with one O(2)Li2SiNi trigonal pyramid, and  an edgeedge with one O(5)LiSiNi2 trigonal pyramid.
Li4Si3(NiO5)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with three equivalent Ni(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. The Li(1)-O(3) bond length is 1.95 Å. The Li(1)-O(5) bond length is 2.09 Å. There is one shorter (1.93 Å) and one longer (1.97 Å) Li(1)-O(2) bond length. In the second Li site, Li(2) is bonded in a distorted pentagonal planar geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. The Li(2)-O(3) bond length is 2.08 Å. There is one shorter (2.03 Å) and one longer (2.11 Å) Li(2)-O(1) bond length. There is one shorter (2.32 Å) and one longer (2.43 Å) Li(2)-O(4) bond length. Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(5) atoms to form NiO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. The Ni(1)-O(1) bond length is 2.11 Å. The Ni(1)-O(2) bond length is 2.07 Å. The Ni(1)-O(3) bond length is 2.03 Å. There is one shorter (2.03 Å) and one longer (2.10 Å) Ni(1)-O(5) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and corners with four equivalent Ni(1)O5 trigonal bipyramids. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.67 Å. The Si(1)-O(5) bond length is 1.64 Å. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. Both Si(2)-O(1) bond lengths are 1.61 Å. Both Si(2)-O(4) bond lengths are 1.66 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Ni(1), and one Si(2) atom to form distorted OLi2SiNi trigonal pyramids that share  a cornercorner with one O(3)Li2SiNi tetrahedra,  a cornercorner with one O(2)Li2SiNi trigonal pyramid, corners with two equivalent O(5)LiSiNi2 trigonal pyramids, corners with three equivalent O(1)Li2SiNi trigonal pyramids, and  an edgeedge with one O(3)Li2SiNi tetrahedra. In the second O site, O(2) is bonded to two equivalent Li(1), one Ni(1), and one Si(1) atom to form distorted OLi2SiNi trigonal pyramids that share corners with four equivalent O(3)Li2SiNi tetrahedra,  a cornercorner with one O(1)Li2SiNi trigonal pyramid, corners with three equivalent O(5)LiSiNi2 trigonal pyramids,  an edgeedge with one O(2)Li2SiNi trigonal pyramid, and  an edgeedge with one O(5)LiSiNi2 trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Ni(1), and one Si(1) atom to form distorted OLi2SiNi tetrahedra that share  a cornercorner with one O(1)Li2SiNi trigonal pyramid, corners with four equivalent O(2)Li2SiNi trigonal pyramids, corners with four equivalent O(5)LiSiNi2 trigonal pyramids, and  an edgeedge with one O(1)Li2SiNi trigonal pyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded to one Li(1), two equivalent Ni(1), and one Si(1) atom to form distorted OLiSiNi2 trigonal pyramids that share corners with four equivalent O(3)Li2SiNi tetrahedra, corners with two equivalent O(1)Li2SiNi trigonal pyramids, corners with three equivalent O(2)Li2SiNi trigonal pyramids,  an edgeedge with one O(2)Li2SiNi trigonal pyramid, and  an edgeedge with one O(5)LiSiNi2 trigonal pyramid.