CsFeSiO4 crystallizes in the orthorhombic Pna2_1 space group. Cs(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form FeO4 tetrahedra that share 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 Fe(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom.
CsFeSiO4 crystallizes in the orthorhombic Pna2_1 space group. Cs(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There is one shorter (3.48 Å) and one longer (3.61 Å) Cs(1)-O(1) bond length. There is one shorter (3.09 Å) and one longer (3.46 Å) Cs(1)-O(2) bond length. There is one shorter (3.14 Å) and one longer (3.38 Å) Cs(1)-O(3) bond length. There is one shorter (3.31 Å) and one longer (3.47 Å) Cs(1)-O(4) bond length. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form FeO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.86 Å. The Fe(1)-O(2) bond length is 1.89 Å. The Fe(1)-O(3) bond length is 1.90 Å. The Fe(1)-O(4) bond length is 1.88 Å. 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 Fe(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.65 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 linear geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Cs(1), one Fe(1), and one Si(1) atom.