La4FeSe6O crystallizes in the hexagonal P6_3mc space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted single-bond geometry to three equivalent Se(1), four equivalent Se(2), and one O(1) atom. In the second La site, La(2) is bonded in a 1-coordinate geometry to three equivalent Se(1), six equivalent Se(2), and one O(1) atom. Fe(1) is bonded to six equivalent Se(1) atoms to form face-sharing FeSe6 octahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one La(2), three equivalent La(1), and two equivalent Fe(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent La(2) and four equivalent La(1) atoms. O(1) is bonded in a tetrahedral geometry to one La(2) and three equivalent La(1) atoms.
La4FeSe6O crystallizes in the hexagonal P6_3mc space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted single-bond geometry to three equivalent Se(1), four equivalent Se(2), and one O(1) atom. There are two shorter (3.05 Å) and one longer (3.10 Å) La(1)-Se(1) bond length. There are two shorter (3.07 Å) and two longer (3.31 Å) La(1)-Se(2) bond lengths. The La(1)-O(1) bond length is 2.42 Å. In the second La site, La(2) is bonded in a 1-coordinate geometry to three equivalent Se(1), six equivalent Se(2), and one O(1) atom. All La(2)-Se(1) bond lengths are 3.59 Å. There are three shorter (2.98 Å) and three longer (3.73 Å) La(2)-Se(2) bond lengths. The La(2)-O(1) bond length is 2.39 Å. Fe(1) is bonded to six equivalent Se(1) atoms to form face-sharing FeSe6 octahedra. There are three shorter (2.65 Å) and three longer (2.85 Å) Fe(1)-Se(1) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one La(2), three equivalent La(1), and two equivalent Fe(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent La(2) and four equivalent La(1) atoms. O(1) is bonded in a tetrahedral geometry to one La(2) and three equivalent La(1) atoms.