Li(NiSi)6 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to six equivalent Ni(1), six equivalent Ni(2), two equivalent Si(2), and six equivalent Si(4) atoms to form distorted LiSi8Ni12 hexagonal bipyramids that share corners with six equivalent Li(2)Si8Ni12 hexagonal bipyramids, faces with six equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with eighteen equivalent Ni(2)Li2Si6Ni4 cuboctahedra, and faces with three equivalent Li(1)Si8Ni12 hexagonal bipyramids. In the second Li site, Li(2) is bonded to twelve equivalent Ni(2), two equivalent Si(1), and six equivalent Si(3) atoms to form distorted LiSi8Ni12 hexagonal bipyramids that share corners with twelve equivalent Li(1)Si8Ni12 hexagonal bipyramids, faces with twelve equivalent Ni(1)Li2Si6Ni4 cuboctahedra, and faces with twelve equivalent Ni(2)Li2Si6Ni4 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Li(1), four equivalent Ni(2), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form distorted NiLi2Si6Ni4 cuboctahedra that share corners with four equivalent Ni(1)Li2Si6Ni4 cuboctahedra, corners with ten equivalent Ni(2)Li2Si6Ni4 cuboctahedra,  an edgeedge with one Ni(1)Li2Si6Ni4 cuboctahedra, edges with six equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with four equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with five equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with two equivalent Li(1)Si8Ni12 hexagonal bipyramids, and faces with two equivalent Li(2)Si8Ni12 hexagonal bipyramids. In the second Ni site, Ni(2) is bonded to one Li(1), one Li(2), two equivalent Ni(1), two equivalent Ni(2), one Si(1), one Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form distorted NiLi2Si6Ni4 cuboctahedra that share corners with five equivalent Ni(1)Li2Si6Ni4 cuboctahedra, corners with nine equivalent Ni(2)Li2Si6Ni4 cuboctahedra, edges with three equivalent Ni(1)Li2Si6Ni4 cuboctahedra, edges with three equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with two equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with eight equivalent Ni(2)Li2Si6Ni4 cuboctahedra,  a faceface with one Li(2)Si8Ni12 hexagonal bipyramid, and faces with three equivalent Li(1)Si8Ni12 hexagonal bipyramids. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Li(2), six equivalent Ni(2), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Li(1), three equivalent Ni(1), three equivalent Ni(2), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Li(2), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to two equivalent Li(1), two equivalent Ni(1), and four equivalent Ni(2) atoms.
Li(NiSi)6 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to six equivalent Ni(1), six equivalent Ni(2), two equivalent Si(2), and six equivalent Si(4) atoms to form distorted LiSi8Ni12 hexagonal bipyramids that share corners with six equivalent Li(2)Si8Ni12 hexagonal bipyramids, faces with six equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with eighteen equivalent Ni(2)Li2Si6Ni4 cuboctahedra, and faces with three equivalent Li(1)Si8Ni12 hexagonal bipyramids. All Li(1)-Ni(1) bond lengths are 3.11 Å. All Li(1)-Ni(2) bond lengths are 3.08 Å. Both Li(1)-Si(2) bond lengths are 2.61 Å. All Li(1)-Si(4) bond lengths are 2.80 Å. In the second Li site, Li(2) is bonded to twelve equivalent Ni(2), two equivalent Si(1), and six equivalent Si(3) atoms to form distorted LiSi8Ni12 hexagonal bipyramids that share corners with twelve equivalent Li(1)Si8Ni12 hexagonal bipyramids, faces with twelve equivalent Ni(1)Li2Si6Ni4 cuboctahedra, and faces with twelve equivalent Ni(2)Li2Si6Ni4 cuboctahedra. All Li(2)-Ni(2) bond lengths are 3.10 Å. Both Li(2)-Si(1) bond lengths are 2.61 Å. All Li(2)-Si(3) bond lengths are 2.79 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Li(1), four equivalent Ni(2), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form distorted NiLi2Si6Ni4 cuboctahedra that share corners with four equivalent Ni(1)Li2Si6Ni4 cuboctahedra, corners with ten equivalent Ni(2)Li2Si6Ni4 cuboctahedra,  an edgeedge with one Ni(1)Li2Si6Ni4 cuboctahedra, edges with six equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with four equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with five equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with two equivalent Li(1)Si8Ni12 hexagonal bipyramids, and faces with two equivalent Li(2)Si8Ni12 hexagonal bipyramids. All Ni(1)-Ni(2) bond lengths are 2.44 Å. Both Ni(1)-Si(2) bond lengths are 2.53 Å. Both Ni(1)-Si(3) bond lengths are 2.34 Å. Both Ni(1)-Si(4) bond lengths are 2.38 Å. In the second Ni site, Ni(2) is bonded to one Li(1), one Li(2), two equivalent Ni(1), two equivalent Ni(2), one Si(1), one Si(2), two equivalent Si(3), and two equivalent Si(4) atoms to form distorted NiLi2Si6Ni4 cuboctahedra that share corners with five equivalent Ni(1)Li2Si6Ni4 cuboctahedra, corners with nine equivalent Ni(2)Li2Si6Ni4 cuboctahedra, edges with three equivalent Ni(1)Li2Si6Ni4 cuboctahedra, edges with three equivalent Ni(2)Li2Si6Ni4 cuboctahedra, faces with two equivalent Ni(1)Li2Si6Ni4 cuboctahedra, faces with eight equivalent Ni(2)Li2Si6Ni4 cuboctahedra,  a faceface with one Li(2)Si8Ni12 hexagonal bipyramid, and faces with three equivalent Li(1)Si8Ni12 hexagonal bipyramids. Both Ni(2)-Ni(2) bond lengths are 2.44 Å. The Ni(2)-Si(1) bond length is 2.54 Å. The Ni(2)-Si(2) bond length is 2.54 Å. Both Ni(2)-Si(3) bond lengths are 2.37 Å. Both Ni(2)-Si(4) bond lengths are 2.36 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Li(2), six equivalent Ni(2), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.37 Å. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Li(1), three equivalent Ni(1), three equivalent Ni(2), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.38 Å. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Li(2), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to two equivalent Li(1), two equivalent Ni(1), and four equivalent Ni(2) atoms.