LiFeSiO4 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded in a trigonal non-coplanar geometry to one O(4) and two equivalent O(2) atoms. Fe(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one 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 three equivalent Fe(1)O5 trigonal bipyramids and  an edgeedge with one Fe(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Fe(1), and one Si(1) atom to form distorted corner-sharing OLi2FeSi tetrahedra. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom.
LiFeSiO4 crystallizes in the orthorhombic Pna2_1 space group. Li(1) is bonded in a trigonal non-coplanar geometry to one O(4) and two equivalent O(2) atoms. The Li(1)-O(4) bond length is 2.09 Å. There is one shorter (1.97 Å) and one longer (2.05 Å) Li(1)-O(2) bond length. Fe(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent Si(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one Si(1)O4 tetrahedra. The Fe(1)-O(2) bond length is 2.09 Å. The Fe(1)-O(3) bond length is 1.91 Å. The Fe(1)-O(4) bond length is 1.91 Å. There is one shorter (1.99 Å) and one longer (2.08 Å) Fe(1)-O(1) 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 three equivalent Fe(1)O5 trigonal bipyramids and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The Si(1)-O(1) bond length is 1.67 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.64 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one Si(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Fe(1), and one Si(1) atom to form distorted corner-sharing OLi2FeSi tetrahedra. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one Si(1) atom.