Li2Fe2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 2-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(7) atom. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(3), one O(4), one O(6), and one O(9) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one O(1), one O(11), and one O(9) atom. In the second Fe site, Fe(2) is bonded in a 2-coordinate geometry to one O(3), one O(8), and one O(9) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Li(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Li(2), one Fe(1), one Fe(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Fe(1) and one Si(2) atom.
Li2Fe2Si4O11 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 2-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and one O(7) atom. The Li(1)-O(1) bond length is 2.41 Å. The Li(1)-O(2) bond length is 1.86 Å. The Li(1)-O(3) bond length is 2.56 Å. The Li(1)-O(5) bond length is 2.53 Å. The Li(1)-O(7) bond length is 1.76 Å. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(3), one O(4), one O(6), and one O(9) atom. The Li(2)-O(3) bond length is 2.10 Å. The Li(2)-O(4) bond length is 1.99 Å. The Li(2)-O(6) bond length is 2.44 Å. The Li(2)-O(9) bond length is 1.89 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one O(1), one O(11), and one O(9) atom. The Fe(1)-O(1) bond length is 1.76 Å. The Fe(1)-O(11) bond length is 1.87 Å. The Fe(1)-O(9) bond length is 2.66 Å. In the second Fe site, Fe(2) is bonded in a 2-coordinate geometry to one O(3), one O(8), and one O(9) atom. The Fe(2)-O(3) bond length is 1.77 Å. The Fe(2)-O(8) bond length is 1.80 Å. The Fe(2)-O(9) bond length is 2.31 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.40 Å. The Si(1)-O(2) bond length is 1.82 Å. The Si(1)-O(3) bond length is 1.48 Å. The Si(1)-O(4) bond length is 2.01 Å. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. The Si(2)-O(10) bond length is 1.59 Å. The Si(2)-O(11) bond length is 1.49 Å. The Si(2)-O(4) bond length is 1.52 Å. The Si(2)-O(5) bond length is 2.08 Å. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(3)-O(2) bond length is 1.62 Å. The Si(3)-O(5) bond length is 1.87 Å. The Si(3)-O(6) bond length is 1.76 Å. The Si(3)-O(8) bond length is 1.42 Å. In the fourth Si site, Si(4) is bonded in a 4-coordinate geometry to one O(10), one O(6), one O(7), and one O(9) atom. The Si(4)-O(10) bond length is 1.95 Å. The Si(4)-O(6) bond length is 1.76 Å. The Si(4)-O(7) bond length is 1.44 Å. The Si(4)-O(9) bond length is 1.55 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Si(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Si(2), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Si(3), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Li(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Si(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Li(2), one Fe(1), one Fe(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Fe(1) and one Si(2) atom.