Li2NiSi2O6 crystallizes in the triclinic P1 space group. There are eight inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), one O(13), one O(20), one O(21), and one O(9) atom. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(19), one O(2), and one O(22) atom. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(11), one O(15), one O(17), one O(23), and one O(3) atom. In the fourth Li site, Li(4) is bonded in a 5-coordinate geometry to one O(12), one O(16), one O(18), one O(24), and one O(4) atom. In the fifth Li site, Li(5) is bonded in a 5-coordinate geometry to one O(1), one O(13), one O(17), one O(23), and one O(9) atom. In the sixth Li site, Li(6) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(18), one O(2), and one O(24) atom. In the seventh Li site, Li(7) is bonded in a 5-coordinate geometry to one O(11), one O(15), one O(19), one O(22), and one O(3) atom. In the eighth Li site, Li(8) is bonded in a 5-coordinate geometry to one O(12), one O(16), one O(20), one O(21), and one O(4) atom. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(14), one O(18), and one O(22) atom to form NiO4 tetrahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(6)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(12), one O(16), one O(20), and one O(24) atom to form NiO4 tetrahedra that share corners with two equivalent Si(4)O4 tetrahedra and corners with two equivalent Si(8)O4 tetrahedra. In the third Ni site, Ni(3) is bonded to one O(13), one O(17), one O(21), and one O(9) atom to form NiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(5)O4 tetrahedra. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(15), one O(19), and one O(23) atom to form NiO4 tetrahedra that share corners with two equivalent Si(3)O4 tetrahedra and corners with two equivalent Si(7)O4 tetrahedra. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(17), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and corners with two equivalent Ni(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(18), one O(2), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and corners with two equivalent Ni(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(11), one O(19), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and corners with two equivalent Ni(4)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(12), one O(20), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and corners with two equivalent Ni(2)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(1), one O(13), one O(21), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Ni(3)O4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(14), one O(2), one O(22), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Ni(1)O4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(15), one O(23), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Ni(4)O4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(16), one O(24), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Ni(2)O4 tetrahedra. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Li(5), one Si(1), and one Si(5) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(2), one Li(6), one Si(2), and one Si(6) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Li(3), one Li(7), one Si(3), and one Si(7) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Li(4), one Li(8), one Si(4), and one Si(8) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Si(1) and one Si(7) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Si(2) and one Si(8) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Si(3) and one Si(6) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Si(4) and one Si(5) atom. In the ninth O site, O(9) is bonded to one Li(1), one Li(5), one Ni(3), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the tenth O site, O(10) is bonded to one Li(2), one Li(6), one Ni(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the eleventh O site, O(11) is bonded to one Li(3), one Li(7), one Ni(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the twelfth O site, O(12) is bonded to one Li(4), one Li(8), one Ni(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the thirteenth O site, O(13) is bonded to one Li(1), one Li(5), one Ni(3), and one Si(5) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the fourteenth O site, O(14) is bonded to one Li(2), one Li(6), one Ni(1), and one Si(6) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the fifteenth O site, O(15) is bonded to one Li(3), one Li(7), one Ni(4), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the sixteenth O site, O(16) is bonded to one Li(4), one Li(8), one Ni(2), and one Si(8) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Li(3), one Li(5), one Ni(3), and one Si(1) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Li(4), one Li(6), one Ni(1), and one Si(2) atom. In the nineteenth O site, O(19) is bonded in a 4-coordinate geometry to one Li(2), one Li(7), one Ni(4), and one Si(3) atom. In the twentieth O site, O(20) is bonded in a 4-coordinate geometry to one Li(1), one Li(8), one Ni(2), and one Si(4) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Li(1), one Li(8), one Ni(3), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 4-coordinate geometry to one Li(2), one Li(7), one Ni(1), and one Si(6) atom. In the twenty-third O site, O(23) is bonded to one Li(3), one Li(5), one Ni(4), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the twenty-fourth O site, O(24) is bonded in a 4-coordinate geometry to one Li(4), one Li(6), one Ni(2), and one Si(8) atom.
Li2NiSi2O6 crystallizes in the triclinic P1 space group. There are eight inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one O(1), one O(13), one O(20), one O(21), and one O(9) atom. The Li(1)-O(1) bond length is 2.40 Å. The Li(1)-O(13) bond length is 2.02 Å. The Li(1)-O(20) bond length is 1.99 Å. The Li(1)-O(21) bond length is 2.52 Å. The Li(1)-O(9) bond length is 2.10 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(19), one O(2), and one O(22) atom. The Li(2)-O(10) bond length is 2.10 Å. The Li(2)-O(14) bond length is 2.02 Å. The Li(2)-O(19) bond length is 1.98 Å. The Li(2)-O(2) bond length is 2.39 Å. The Li(2)-O(22) bond length is 2.54 Å. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(11), one O(15), one O(17), one O(23), and one O(3) atom. The Li(3)-O(11) bond length is 2.09 Å. The Li(3)-O(15) bond length is 2.03 Å. The Li(3)-O(17) bond length is 1.98 Å. The Li(3)-O(23) bond length is 2.52 Å. The Li(3)-O(3) bond length is 2.41 Å. In the fourth Li site, Li(4) is bonded in a 5-coordinate geometry to one O(12), one O(16), one O(18), one O(24), and one O(4) atom. The Li(4)-O(12) bond length is 2.09 Å. The Li(4)-O(16) bond length is 2.02 Å. The Li(4)-O(18) bond length is 1.99 Å. The Li(4)-O(24) bond length is 2.54 Å. The Li(4)-O(4) bond length is 2.39 Å. In the fifth Li site, Li(5) is bonded in a 5-coordinate geometry to one O(1), one O(13), one O(17), one O(23), and one O(9) atom. The Li(5)-O(1) bond length is 2.41 Å. The Li(5)-O(13) bond length is 2.06 Å. The Li(5)-O(17) bond length is 2.54 Å. The Li(5)-O(23) bond length is 1.98 Å. The Li(5)-O(9) bond length is 2.02 Å. In the sixth Li site, Li(6) is bonded in a 5-coordinate geometry to one O(10), one O(14), one O(18), one O(2), and one O(24) atom. The Li(6)-O(10) bond length is 2.02 Å. The Li(6)-O(14) bond length is 2.05 Å. The Li(6)-O(18) bond length is 2.55 Å. The Li(6)-O(2) bond length is 2.41 Å. The Li(6)-O(24) bond length is 1.97 Å. In the seventh Li site, Li(7) is bonded in a 5-coordinate geometry to one O(11), one O(15), one O(19), one O(22), and one O(3) atom. The Li(7)-O(11) bond length is 2.01 Å. The Li(7)-O(15) bond length is 2.07 Å. The Li(7)-O(19) bond length is 2.54 Å. The Li(7)-O(22) bond length is 1.98 Å. The Li(7)-O(3) bond length is 2.40 Å. In the eighth Li site, Li(8) is bonded in a 5-coordinate geometry to one O(12), one O(16), one O(20), one O(21), and one O(4) atom. The Li(8)-O(12) bond length is 2.02 Å. The Li(8)-O(16) bond length is 2.04 Å. The Li(8)-O(20) bond length is 2.56 Å. The Li(8)-O(21) bond length is 1.97 Å. The Li(8)-O(4) bond length is 2.41 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(14), one O(18), and one O(22) atom to form NiO4 tetrahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(6)O4 tetrahedra. The Ni(1)-O(10) bond length is 2.02 Å. The Ni(1)-O(14) bond length is 2.01 Å. The Ni(1)-O(18) bond length is 1.99 Å. The Ni(1)-O(22) bond length is 2.00 Å. In the second Ni site, Ni(2) is bonded to one O(12), one O(16), one O(20), and one O(24) atom to form NiO4 tetrahedra that share corners with two equivalent Si(4)O4 tetrahedra and corners with two equivalent Si(8)O4 tetrahedra. The Ni(2)-O(12) bond length is 2.02 Å. The Ni(2)-O(16) bond length is 2.01 Å. The Ni(2)-O(20) bond length is 1.99 Å. The Ni(2)-O(24) bond length is 2.00 Å. In the third Ni site, Ni(3) is bonded to one O(13), one O(17), one O(21), and one O(9) atom to form NiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(5)O4 tetrahedra. The Ni(3)-O(13) bond length is 2.01 Å. The Ni(3)-O(17) bond length is 1.99 Å. The Ni(3)-O(21) bond length is 2.00 Å. The Ni(3)-O(9) bond length is 2.02 Å. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(15), one O(19), and one O(23) atom to form NiO4 tetrahedra that share corners with two equivalent Si(3)O4 tetrahedra and corners with two equivalent Si(7)O4 tetrahedra. The Ni(4)-O(11) bond length is 2.01 Å. The Ni(4)-O(15) bond length is 2.02 Å. The Ni(4)-O(19) bond length is 2.00 Å. The Ni(4)-O(23) bond length is 1.99 Å. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(17), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and corners with two equivalent Ni(3)O4 tetrahedra. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(17) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.63 Å. The Si(1)-O(9) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(10), one O(18), one O(2), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and corners with two equivalent Ni(1)O4 tetrahedra. The Si(2)-O(10) bond length is 1.63 Å. The Si(2)-O(18) bond length is 1.63 Å. The Si(2)-O(2) bond length is 1.67 Å. The Si(2)-O(6) bond length is 1.63 Å. In the third Si site, Si(3) is bonded to one O(11), one O(19), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and corners with two equivalent Ni(4)O4 tetrahedra. The Si(3)-O(11) bond length is 1.63 Å. The Si(3)-O(19) bond length is 1.63 Å. The Si(3)-O(3) bond length is 1.67 Å. The Si(3)-O(7) bond length is 1.63 Å. In the fourth Si site, Si(4) is bonded to one O(12), one O(20), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and corners with two equivalent Ni(2)O4 tetrahedra. The Si(4)-O(12) bond length is 1.63 Å. The Si(4)-O(20) bond length is 1.63 Å. The Si(4)-O(4) bond length is 1.67 Å. The Si(4)-O(8) bond length is 1.63 Å. In the fifth Si site, Si(5) is bonded to one O(1), one O(13), one O(21), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Ni(3)O4 tetrahedra. The Si(5)-O(1) bond length is 1.67 Å. The Si(5)-O(13) bond length is 1.63 Å. The Si(5)-O(21) bond length is 1.63 Å. The Si(5)-O(8) bond length is 1.63 Å. In the sixth Si site, Si(6) is bonded to one O(14), one O(2), one O(22), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Ni(1)O4 tetrahedra. The Si(6)-O(14) bond length is 1.63 Å. The Si(6)-O(2) bond length is 1.67 Å. The Si(6)-O(22) bond length is 1.62 Å. The Si(6)-O(7) bond length is 1.63 Å. In the seventh Si site, Si(7) is bonded to one O(15), one O(23), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Ni(4)O4 tetrahedra. The Si(7)-O(15) bond length is 1.63 Å. The Si(7)-O(23) bond length is 1.63 Å. The Si(7)-O(3) bond length is 1.67 Å. The Si(7)-O(5) bond length is 1.63 Å. In the eighth Si site, Si(8) is bonded to one O(16), one O(24), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Ni(2)O4 tetrahedra. The Si(8)-O(16) bond length is 1.63 Å. The Si(8)-O(24) bond length is 1.62 Å. The Si(8)-O(4) bond length is 1.67 Å. The Si(8)-O(6) bond length is 1.63 Å. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Li(5), one Si(1), and one Si(5) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(2), one Li(6), one Si(2), and one Si(6) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Li(3), one Li(7), one Si(3), and one Si(7) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Li(4), one Li(8), one Si(4), and one Si(8) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Si(1) and one Si(7) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Si(2) and one Si(8) atom. In the seventh O site, O(7) is bonded in a linear geometry to one Si(3) and one Si(6) atom. In the eighth O site, O(8) is bonded in a linear geometry to one Si(4) and one Si(5) atom. In the ninth O site, O(9) is bonded to one Li(1), one Li(5), one Ni(3), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the tenth O site, O(10) is bonded to one Li(2), one Li(6), one Ni(1), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the eleventh O site, O(11) is bonded to one Li(3), one Li(7), one Ni(4), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the twelfth O site, O(12) is bonded to one Li(4), one Li(8), one Ni(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the thirteenth O site, O(13) is bonded to one Li(1), one Li(5), one Ni(3), and one Si(5) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the fourteenth O site, O(14) is bonded to one Li(2), one Li(6), one Ni(1), and one Si(6) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the fifteenth O site, O(15) is bonded to one Li(3), one Li(7), one Ni(4), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the sixteenth O site, O(16) is bonded to one Li(4), one Li(8), one Ni(2), and one Si(8) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi tetrahedra. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Li(3), one Li(5), one Ni(3), and one Si(1) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one Li(4), one Li(6), one Ni(1), and one Si(2) atom. In the nineteenth O site, O(19) is bonded in a 4-coordinate geometry to one Li(2), one Li(7), one Ni(4), and one Si(3) atom. In the twentieth O site, O(20) is bonded in a 4-coordinate geometry to one Li(1), one Li(8), one Ni(2), and one Si(4) atom. In the twenty-first O site, O(21) is bonded in a 4-coordinate geometry to one Li(1), one Li(8), one Ni(3), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 4-coordinate geometry to one Li(2), one Li(7), one Ni(1), and one Si(6) atom. In the twenty-third O site, O(23) is bonded to one Li(3), one Li(5), one Ni(4), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OLi2SiNi trigonal pyramids. In the twenty-fourth O site, O(24) is bonded in a 4-coordinate geometry to one Li(4), one Li(6), one Ni(2), and one Si(8) atom.