LiFeSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Fe(1)O6 octahedra. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiFe2Si trigonal pyramids. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Li(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Li(1), one Fe(1), and one Si(1) atom.
LiFeSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Li(1)-O(1) bond lengths are 2.04 Å. Both Li(1)-O(2) bond lengths are 2.59 Å. Both Li(1)-O(3) bond lengths are 2.17 Å. Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Fe(1)O6 octahedra. Both Fe(1)-O(3) bond lengths are 1.94 Å. There are two shorter (2.05 Å) and two longer (2.18 Å) Fe(1)-O(1) bond lengths. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-60°. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.62 Å. Both Si(1)-O(2) bond lengths are 1.64 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiFe2Si trigonal pyramids. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Li(1) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Li(1), one Fe(1), and one Si(1) atom.