LiFeSiO4 crystallizes in the trigonal R-3 space group. Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent Fe(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Si(1) atom.
LiFeSiO4 crystallizes in the trigonal R-3 space group. Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. The Li(1)-O(2) bond length is 2.08 Å. The Li(1)-O(3) bond length is 2.10 Å. There is one shorter (1.87 Å) and one longer (1.91 Å) Li(1)-O(1) bond length. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. The Fe(1)-O(2) bond length is 1.86 Å. The Fe(1)-O(3) bond length is 1.86 Å. There is one shorter (1.97 Å) and one longer (1.98 Å) Fe(1)-O(4) bond length. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent Fe(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.58 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.67 Å. The Si(1)-O(4) bond length is 1.72 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Li(1) and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Si(1) atom.