BaFeSi4O10 crystallizes in the tetragonal P4/nmm space group. Ba(1) is bonded in a 12-coordinate geometry to four equivalent O(3) and eight equivalent O(2) atoms. Fe(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(2) atoms. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ba(1) and two equivalent Si(1) atoms.
BaFeSi4O10 crystallizes in the tetragonal P4/nmm space group. Ba(1) is bonded in a 12-coordinate geometry to four equivalent O(3) and eight equivalent O(2) atoms. All Ba(1)-O(3) bond lengths are 2.94 Å. All Ba(1)-O(2) bond lengths are 3.14 Å. Fe(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(2) atoms. All Fe(1)-O(2) bond lengths are 2.01 Å. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.60 Å. Both Si(1)-O(3) bond lengths are 1.65 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ba(1) and two equivalent Si(1) atoms.