Li2Fe(Si2O5)3 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(10), one O(15), and one O(4) atom. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(1), one O(14), one O(2), and one O(6) atom. Fe(1) is bonded to one O(1), one O(14), one O(4), one O(6), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)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(2), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the second Si site, Si(2) is bonded to one O(1), one O(11), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  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 corner-sharing octahedral tilt angles are 58°. In the third Si site, Si(3) is bonded to one O(10), one O(12), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. In the fourth Si site, Si(4) is bonded to one O(12), one O(13), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. In the fifth Si site, Si(5) is bonded to one O(10), one O(11), one O(15), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. In the sixth Si site, Si(6) is bonded to one O(13), one O(14), one O(15), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), 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(4) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Li(2), one Fe(1), and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(6) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(5) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Si(3), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(6) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Li(1), one Si(5), and one Si(6) atom.
Li2Fe(Si2O5)3 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(10), one O(15), and one O(4) atom. The Li(1)-O(1) bond length is 1.95 Å. The Li(1)-O(10) bond length is 2.55 Å. The Li(1)-O(15) bond length is 2.09 Å. The Li(1)-O(4) bond length is 1.97 Å. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(1), one O(14), one O(2), and one O(6) atom. The Li(2)-O(1) bond length is 2.10 Å. The Li(2)-O(14) bond length is 2.07 Å. The Li(2)-O(2) bond length is 2.13 Å. The Li(2)-O(6) bond length is 2.61 Å. Fe(1) is bonded to one O(1), one O(14), one O(4), one O(6), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)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 2.30 Å. The Fe(1)-O(14) bond length is 2.13 Å. The Fe(1)-O(4) bond length is 1.98 Å. The Fe(1)-O(6) bond length is 1.91 Å. The Fe(1)-O(7) bond length is 1.89 Å. The Fe(1)-O(9) bond length is 1.89 Å. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.62 Å. The Si(1)-O(5) bond length is 1.63 Å. The Si(1)-O(8) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(1), one O(11), one O(2), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  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 corner-sharing octahedral tilt angles are 58°. The Si(2)-O(1) bond length is 1.62 Å. The Si(2)-O(11) bond length is 1.65 Å. The Si(2)-O(2) bond length is 1.68 Å. The Si(2)-O(3) bond length is 1.62 Å. In the third Si site, Si(3) is bonded to one O(10), one O(12), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. The Si(3)-O(10) bond length is 1.66 Å. The Si(3)-O(12) bond length is 1.62 Å. The Si(3)-O(3) bond length is 1.63 Å. The Si(3)-O(6) bond length is 1.62 Å. In the fourth Si site, Si(4) is bonded to one O(12), one O(13), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. The Si(4)-O(12) bond length is 1.63 Å. The Si(4)-O(13) bond length is 1.65 Å. The Si(4)-O(5) bond length is 1.64 Å. The Si(4)-O(7) bond length is 1.61 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(11), one O(15), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. The Si(5)-O(10) bond length is 1.65 Å. The Si(5)-O(11) bond length is 1.64 Å. The Si(5)-O(15) bond length is 1.66 Å. The Si(5)-O(9) bond length is 1.62 Å. In the sixth Si site, Si(6) is bonded to one O(13), one O(14), one O(15), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. The Si(6)-O(13) bond length is 1.64 Å. The Si(6)-O(14) bond length is 1.61 Å. The Si(6)-O(15) bond length is 1.67 Å. The Si(6)-O(8) bond length is 1.63 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), 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(4) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Li(2), one Fe(1), and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(6) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(1) and one Si(5) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Si(3), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Si(6) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Li(1), one Si(5), and one Si(6) atom.