Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi trigonal pyramids.
Li2FeSiO4 is beta beryllia-derived structured and crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. Both Li(1)-O(1) bond lengths are 2.00 Å. Both Li(1)-O(2) bond lengths are 2.08 Å. In the second Li site, Li(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. Both Li(2)-O(1) bond lengths are 2.06 Å. Both Li(2)-O(2) bond lengths are 1.94 Å. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Both Fe(1)-O(1) bond lengths are 2.05 Å. Both Fe(1)-O(2) bond lengths are 2.01 Å. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. Both Si(1)-O(1) bond lengths are 1.66 Å. Both Si(1)-O(2) bond lengths are 1.66 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of edge and corner-sharing OLi2FeSi tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2FeSi trigonal pyramids.