Li2FeSiO4 is Stannite-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(3), one O(5), one O(7), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(5), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. There are two 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(5) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Fe(1), one Fe(2), and one Si(1) atom to form OLiFe2Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Li(4), and one Si(1) atom to form OLi3Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, and corners with two equivalent O(1)LiFe2Si tetrahedra. In the third O site, O(3) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(1) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(2) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the fifth O site, O(5) is bonded to one Li(3), one Li(4), one Fe(1), and one Si(1) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the sixth O site, O(6) is bonded to one Li(2), one Li(4), one Fe(1), and one Si(2) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Li(4), and one Si(2) atom to form OLi3Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the eighth O site, O(8) is bonded to one Li(3), one Fe(1), one Fe(2), and one Si(2) atom to form distorted OLiFe2Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, and corners with two equivalent O(1)LiFe2Si tetrahedra.
Li2FeSiO4 is Stannite-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Li(1)-O(2) bond length is 2.00 Å. The Li(1)-O(3) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.03 Å. The Li(1)-O(7) bond length is 1.98 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Li(2)-O(1) bond length is 2.16 Å. The Li(2)-O(2) bond length is 1.96 Å. The Li(2)-O(4) bond length is 2.03 Å. The Li(2)-O(6) bond length is 2.00 Å. In the third Li site, Li(3) is bonded to one O(3), one O(5), one O(7), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Li(3)-O(3) bond length is 1.98 Å. The Li(3)-O(5) bond length is 2.03 Å. The Li(3)-O(7) bond length is 1.96 Å. The Li(3)-O(8) bond length is 2.14 Å. In the fourth Li site, Li(4) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Li(4)-O(2) bond length is 1.99 Å. The Li(4)-O(5) bond length is 2.02 Å. The Li(4)-O(6) bond length is 1.98 Å. The Li(4)-O(7) bond length is 2.00 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(5), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Fe(1)-O(1) bond length is 2.04 Å. The Fe(1)-O(5) bond length is 1.99 Å. The Fe(1)-O(6) bond length is 2.00 Å. The Fe(1)-O(8) bond length is 2.02 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(4), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The Fe(2)-O(1) bond length is 2.06 Å. The Fe(2)-O(3) bond length is 1.98 Å. The Fe(2)-O(4) bond length is 1.98 Å. The Fe(2)-O(8) bond length is 2.02 Å. There are two 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(5) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. The Si(1)-O(1) bond length is 1.69 Å. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.66 Å. The Si(1)-O(5) bond length is 1.66 Å. In the second Si site, Si(2) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. The Si(2)-O(4) bond length is 1.66 Å. The Si(2)-O(6) bond length is 1.65 Å. The Si(2)-O(7) bond length is 1.62 Å. The Si(2)-O(8) bond length is 1.69 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Fe(1), one Fe(2), and one Si(1) atom to form OLiFe2Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Li(4), and one Si(1) atom to form OLi3Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, and corners with two equivalent O(1)LiFe2Si tetrahedra. In the third O site, O(3) is bonded to one Li(1), one Li(3), one Fe(2), and one Si(1) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Fe(2), and one Si(2) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the fifth O site, O(5) is bonded to one Li(3), one Li(4), one Fe(1), and one Si(1) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the sixth O site, O(6) is bonded to one Li(2), one Li(4), one Fe(1), and one Si(2) atom to form OLi2FeSi tetrahedra that share corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, corners with two equivalent O(1)LiFe2Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the seventh O site, O(7) is bonded to one Li(1), one Li(3), one Li(4), and one Si(2) atom to form OLi3Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, and corners with two equivalent O(8)LiFe2Si tetrahedra. In the eighth O site, O(8) is bonded to one Li(3), one Fe(1), one Fe(2), and one Si(2) atom to form distorted OLiFe2Si tetrahedra that share corners with two equivalent O(3)Li2FeSi tetrahedra, corners with two equivalent O(4)Li2FeSi tetrahedra, corners with two equivalent O(5)Li2FeSi tetrahedra, corners with two equivalent O(6)Li2FeSi tetrahedra, corners with two equivalent O(7)Li3Si tetrahedra, and corners with two equivalent O(1)LiFe2Si tetrahedra.