Li2SnP2O7 crystallizes in the triclinic P1 space group. There are eight inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal non-coplanar geometry to one O(4), one O(5), and one O(9) atom. In the second Li site, Li(2) is bonded to one O(2), one O(22), one O(4), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra, and  an edgeedge with one Li(7)O4 tetrahedra. In the third Li site, Li(3) is bonded in a distorted trigonal planar geometry to one O(12), one O(19), and one O(26) atom. In the fourth Li site, Li(4) is bonded in a distorted T-shaped geometry to one O(11), one O(28), and one O(8) atom. In the fifth Li site, Li(5) is bonded in a 4-coordinate geometry to one O(10), one O(17), one O(3), and one O(6) atom. In the sixth Li site, Li(6) is bonded to one O(1), one O(13), one O(18), and one O(21) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and  a cornercorner with one P(6)O4 tetrahedra. In the seventh Li site, Li(7) is bonded to one O(22), one O(25), one O(27), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. In the eighth Li site, Li(8) is bonded in a trigonal non-coplanar geometry to one O(20), one O(25), and one O(4) atom. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(10), one O(12), one O(3), one O(5), and one O(9) atom to form distorted SnO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and corners with two equivalent P(5)O4 tetrahedra. In the second Sn site, Sn(2) is bonded in a distorted rectangular see-saw-like geometry to one O(13), one O(27), one O(28), and one O(8) atom. In the third Sn site, Sn(3) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(16), one O(2), and one O(21) atom. In the fourth Sn site, Sn(4) is bonded in a distorted rectangular see-saw-like geometry to one O(19), one O(20), one O(24), and one O(26) atom. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. In the second P site, P(2) is bonded to one O(13), one O(19), one O(2), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. In the third P site, P(3) is bonded to one O(11), one O(15), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, and  a cornercorner with one P(5)O4 tetrahedra. In the fourth P site, P(4) is bonded to one O(14), one O(17), one O(24), and one O(8) atom to form corner-sharing PO4 tetrahedra. In the fifth P site, P(5) is bonded to one O(12), one O(15), one O(21), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. In the sixth P site, P(6) is bonded to one O(14), one O(18), one O(20), and one O(22) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. In the seventh P site, P(7) is bonded to one O(10), one O(16), one O(23), and one O(27) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. In the eighth P site, P(8) is bonded to one O(23), one O(25), one O(26), and one O(28) atom to form PO4 tetrahedra that share  a cornercorner with one Li(7)O4 tetrahedra and  a cornercorner with one P(7)O4 tetrahedra. There are twenty-eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(6), one Sn(3), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one Sn(3), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(5), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Li(8), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(5) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(5), one P(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Li(2), one Li(7), and one P(3) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(4), one Sn(2), and one P(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(5), one Sn(1), and one P(7) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Li(4) and one P(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Li(3), one Sn(1), and one P(5) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(6), one Sn(2), and one P(2) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one P(4) and one P(6) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(3) and one P(5) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Sn(3) and one P(7) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Li(5) and one P(4) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Li(6) and one P(6) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 120 degrees geometry to one Li(3), one Sn(4), and one P(2) atom. In the twentieth O site, O(20) is bonded in a distorted trigonal planar geometry to one Li(8), one Sn(4), and one P(6) atom. In the twenty-first O site, O(21) is bonded in a 3-coordinate geometry to one Li(6), one Sn(3), and one P(5) atom. In the twenty-second O site, O(22) is bonded in a distorted T-shaped geometry to one Li(2), one Li(7), and one P(6) atom. In the twenty-third O site, O(23) is bonded in a distorted bent 120 degrees geometry to one P(7) and one P(8) atom. In the twenty-fourth O site, O(24) is bonded in a 2-coordinate geometry to one Sn(4) and one P(4) atom. In the twenty-fifth O site, O(25) is bonded in a trigonal planar geometry to one Li(7), one Li(8), and one P(8) atom. In the twenty-sixth O site, O(26) is bonded in a distorted trigonal non-coplanar geometry to one Li(3), one Sn(4), and one P(8) atom. In the twenty-seventh O site, O(27) is bonded in a 3-coordinate geometry to one Li(7), one Sn(2), and one P(7) atom. In the twenty-eighth O site, O(28) is bonded in a 3-coordinate geometry to one Li(4), one Sn(2), and one P(8) atom.
Li2SnP2O7 crystallizes in the triclinic P1 space group. There are eight inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal non-coplanar geometry to one O(4), one O(5), and one O(9) atom. The Li(1)-O(4) bond length is 1.97 Å. The Li(1)-O(5) bond length is 1.97 Å. The Li(1)-O(9) bond length is 1.99 Å. In the second Li site, Li(2) is bonded to one O(2), one O(22), one O(4), and one O(7) atom to form distorted LiO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra, and  an edgeedge with one Li(7)O4 tetrahedra. The Li(2)-O(2) bond length is 1.89 Å. The Li(2)-O(22) bond length is 1.98 Å. The Li(2)-O(4) bond length is 2.30 Å. The Li(2)-O(7) bond length is 1.88 Å. In the third Li site, Li(3) is bonded in a distorted trigonal planar geometry to one O(12), one O(19), and one O(26) atom. The Li(3)-O(12) bond length is 1.93 Å. The Li(3)-O(19) bond length is 1.93 Å. The Li(3)-O(26) bond length is 2.03 Å. In the fourth Li site, Li(4) is bonded in a distorted T-shaped geometry to one O(11), one O(28), and one O(8) atom. The Li(4)-O(11) bond length is 1.87 Å. The Li(4)-O(28) bond length is 2.07 Å. The Li(4)-O(8) bond length is 1.95 Å. In the fifth Li site, Li(5) is bonded in a 4-coordinate geometry to one O(10), one O(17), one O(3), and one O(6) atom. The Li(5)-O(10) bond length is 1.95 Å. The Li(5)-O(17) bond length is 1.89 Å. The Li(5)-O(3) bond length is 2.37 Å. The Li(5)-O(6) bond length is 2.12 Å. In the sixth Li site, Li(6) is bonded to one O(1), one O(13), one O(18), and one O(21) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and  a cornercorner with one P(6)O4 tetrahedra. The Li(6)-O(1) bond length is 2.11 Å. The Li(6)-O(13) bond length is 2.31 Å. The Li(6)-O(18) bond length is 1.90 Å. The Li(6)-O(21) bond length is 1.98 Å. In the seventh Li site, Li(7) is bonded to one O(22), one O(25), one O(27), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra,  a cornercorner with one P(8)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The Li(7)-O(22) bond length is 1.91 Å. The Li(7)-O(25) bond length is 2.08 Å. The Li(7)-O(27) bond length is 1.94 Å. The Li(7)-O(7) bond length is 2.06 Å. In the eighth Li site, Li(8) is bonded in a trigonal non-coplanar geometry to one O(20), one O(25), and one O(4) atom. The Li(8)-O(20) bond length is 1.91 Å. The Li(8)-O(25) bond length is 1.92 Å. The Li(8)-O(4) bond length is 2.13 Å. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(10), one O(12), one O(3), one O(5), and one O(9) atom to form distorted SnO5 square pyramids that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(7)O4 tetrahedra, and corners with two equivalent P(5)O4 tetrahedra. The Sn(1)-O(10) bond length is 2.48 Å. The Sn(1)-O(12) bond length is 2.54 Å. The Sn(1)-O(3) bond length is 2.34 Å. The Sn(1)-O(5) bond length is 2.41 Å. The Sn(1)-O(9) bond length is 2.29 Å. In the second Sn site, Sn(2) is bonded in a distorted rectangular see-saw-like geometry to one O(13), one O(27), one O(28), and one O(8) atom. The Sn(2)-O(13) bond length is 2.37 Å. The Sn(2)-O(27) bond length is 2.53 Å. The Sn(2)-O(28) bond length is 2.28 Å. The Sn(2)-O(8) bond length is 2.36 Å. In the third Sn site, Sn(3) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(16), one O(2), and one O(21) atom. The Sn(3)-O(1) bond length is 2.28 Å. The Sn(3)-O(16) bond length is 2.36 Å. The Sn(3)-O(2) bond length is 2.51 Å. The Sn(3)-O(21) bond length is 2.38 Å. In the fourth Sn site, Sn(4) is bonded in a distorted rectangular see-saw-like geometry to one O(19), one O(20), one O(24), and one O(26) atom. The Sn(4)-O(19) bond length is 2.57 Å. The Sn(4)-O(20) bond length is 2.26 Å. The Sn(4)-O(24) bond length is 2.23 Å. The Sn(4)-O(26) bond length is 2.36 Å. There are eight inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.65 Å. In the second P site, P(2) is bonded to one O(13), one O(19), one O(2), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. The P(2)-O(13) bond length is 1.55 Å. The P(2)-O(19) bond length is 1.52 Å. The P(2)-O(2) bond length is 1.52 Å. The P(2)-O(6) bond length is 1.65 Å. In the third P site, P(3) is bonded to one O(11), one O(15), one O(7), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra, and  a cornercorner with one P(5)O4 tetrahedra. The P(3)-O(11) bond length is 1.51 Å. The P(3)-O(15) bond length is 1.65 Å. The P(3)-O(7) bond length is 1.53 Å. The P(3)-O(9) bond length is 1.56 Å. In the fourth P site, P(4) is bonded to one O(14), one O(17), one O(24), and one O(8) atom to form corner-sharing PO4 tetrahedra. The P(4)-O(14) bond length is 1.64 Å. The P(4)-O(17) bond length is 1.52 Å. The P(4)-O(24) bond length is 1.54 Å. The P(4)-O(8) bond length is 1.55 Å. In the fifth P site, P(5) is bonded to one O(12), one O(15), one O(21), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O5 square pyramids,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. The P(5)-O(12) bond length is 1.54 Å. The P(5)-O(15) bond length is 1.64 Å. The P(5)-O(21) bond length is 1.54 Å. The P(5)-O(5) bond length is 1.54 Å. In the sixth P site, P(6) is bonded to one O(14), one O(18), one O(20), and one O(22) atom to form PO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(7)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  a cornercorner with one Li(6)O4 trigonal pyramid. The P(6)-O(14) bond length is 1.63 Å. The P(6)-O(18) bond length is 1.52 Å. The P(6)-O(20) bond length is 1.56 Å. The P(6)-O(22) bond length is 1.53 Å. In the seventh P site, P(7) is bonded to one O(10), one O(16), one O(23), and one O(27) atom to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O5 square pyramid,  a cornercorner with one Li(7)O4 tetrahedra, and  a cornercorner with one P(8)O4 tetrahedra. The P(7)-O(10) bond length is 1.53 Å. The P(7)-O(16) bond length is 1.56 Å. The P(7)-O(23) bond length is 1.64 Å. The P(7)-O(27) bond length is 1.52 Å. In the eighth P site, P(8) is bonded to one O(23), one O(25), one O(26), and one O(28) atom to form PO4 tetrahedra that share  a cornercorner with one Li(7)O4 tetrahedra and  a cornercorner with one P(7)O4 tetrahedra. The P(8)-O(23) bond length is 1.64 Å. The P(8)-O(25) bond length is 1.52 Å. The P(8)-O(26) bond length is 1.54 Å. The P(8)-O(28) bond length is 1.56 Å. There are twenty-eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(6), one Sn(3), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(2), one Sn(3), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(5), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Li(1), one Li(2), one Li(8), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(5) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(5), one P(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Li(2), one Li(7), and one P(3) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(4), one Sn(2), and one P(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(1), one Sn(1), and one P(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(5), one Sn(1), and one P(7) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Li(4) and one P(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Li(3), one Sn(1), and one P(5) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(6), one Sn(2), and one P(2) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one P(4) and one P(6) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(3) and one P(5) atom. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to one Sn(3) and one P(7) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Li(5) and one P(4) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Li(6) and one P(6) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 120 degrees geometry to one Li(3), one Sn(4), and one P(2) atom. In the twentieth O site, O(20) is bonded in a distorted trigonal planar geometry to one Li(8), one Sn(4), and one P(6) atom. In the twenty-first O site, O(21) is bonded in a 3-coordinate geometry to one Li(6), one Sn(3), and one P(5) atom. In the twenty-second O site, O(22) is bonded in a distorted T-shaped geometry to one Li(2), one Li(7), and one P(6) atom. In the twenty-third O site, O(23) is bonded in a distorted bent 120 degrees geometry to one P(7) and one P(8) atom. In the twenty-fourth O site, O(24) is bonded in a 2-coordinate geometry to one Sn(4) and one P(4) atom. In the twenty-fifth O site, O(25) is bonded in a trigonal planar geometry to one Li(7), one Li(8), and one P(8) atom. In the twenty-sixth O site, O(26) is bonded in a distorted trigonal non-coplanar geometry to one Li(3), one Sn(4), and one P(8) atom. In the twenty-seventh O site, O(27) is bonded in a 3-coordinate geometry to one Li(7), one Sn(2), and one P(7) atom. In the twenty-eighth O site, O(28) is bonded in a 3-coordinate geometry to one Li(4), one Sn(2), and one P(8) atom.