Li2Fe(Si2O5)3 crystallizes in the monoclinic Cc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), and one O(6) atom. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one O(2), one O(4), and one O(6) atom. Fe(1) is bonded to one O(1), one O(10), one O(15), one O(2), and one O(4) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(14), one O(15), one O(3), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(12), one O(6), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(13), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(1), one O(12), one O(14), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(6) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(5) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(6) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Si(3) and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(2) atom.
Li2Fe(Si2O5)3 crystallizes in the monoclinic Cc space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), and one O(6) atom. The Li(1)-O(1) bond length is 1.96 Å. The Li(1)-O(4) bond length is 2.41 Å. The Li(1)-O(6) bond length is 1.87 Å. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one O(2), one O(4), and one O(6) atom. The Li(2)-O(2) bond length is 2.08 Å. The Li(2)-O(4) bond length is 1.99 Å. The Li(2)-O(6) bond length is 1.91 Å. Fe(1) is bonded to one O(1), one O(10), one O(15), one O(2), and one O(4) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.92 Å. The Fe(1)-O(10) bond length is 1.90 Å. The Fe(1)-O(15) bond length is 1.87 Å. The Fe(1)-O(2) bond length is 1.94 Å. The Fe(1)-O(4) bond length is 1.96 Å. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The Si(1)-O(13) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.62 Å. The Si(1)-O(5) bond length is 1.62 Å. The Si(1)-O(7) bond length is 1.64 Å. In the second Si site, Si(2) is bonded to one O(14), one O(15), one O(3), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The Si(2)-O(14) bond length is 1.63 Å. The Si(2)-O(15) bond length is 1.63 Å. The Si(2)-O(3) bond length is 1.64 Å. The Si(2)-O(8) bond length is 1.64 Å. In the third Si site, Si(3) is bonded to one O(12), one O(6), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. The Si(3)-O(12) bond length is 1.65 Å. The Si(3)-O(6) bond length is 1.61 Å. The Si(3)-O(8) bond length is 1.66 Å. The Si(3)-O(9) bond length is 1.64 Å. In the fourth Si site, Si(4) is bonded to one O(10), one O(11), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The Si(4)-O(10) bond length is 1.60 Å. The Si(4)-O(11) bond length is 1.66 Å. The Si(4)-O(7) bond length is 1.64 Å. The Si(4)-O(9) bond length is 1.63 Å. In the fifth Si site, Si(5) is bonded to one O(11), one O(13), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(4)O4 tetrahedra. The Si(5)-O(11) bond length is 1.64 Å. The Si(5)-O(13) bond length is 1.64 Å. The Si(5)-O(2) bond length is 1.64 Å. The Si(5)-O(3) bond length is 1.64 Å. In the sixth Si site, Si(6) is bonded to one O(1), one O(12), one O(14), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The Si(6)-O(1) bond length is 1.63 Å. The Si(6)-O(12) bond length is 1.63 Å. The Si(6)-O(14) bond length is 1.64 Å. The Si(6)-O(5) bond length is 1.64 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(6) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(5) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(5) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(6) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Si(3) and one Si(6) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(2) atom.