K3FeO4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded in a tetrahedral geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one K(2), four equivalent K(1), and one Fe(1) atom to form distorted edge-sharing OK5Fe octahedra. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(2), four equivalent K(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(2), three equivalent K(1), and one Fe(1) atom.
K3FeO4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. There is one shorter (2.71 Å) and one longer (2.76 Å) K(1)-O(1) bond length. There is one shorter (2.80 Å) and one longer (3.05 Å) K(1)-O(2) bond length. There are a spread of K(1)-O(3) bond distances ranging from 2.71-2.79 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), and four equivalent O(3) atoms. The K(2)-O(1) bond length is 2.61 Å. There is one shorter (2.70 Å) and one longer (3.05 Å) K(2)-O(2) bond length. There are two shorter (3.07 Å) and two longer (3.11 Å) K(2)-O(3) bond lengths. Fe(1) is bonded in a tetrahedral geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Fe(1)-O(1) bond length is 1.69 Å. The Fe(1)-O(2) bond length is 1.70 Å. Both Fe(1)-O(3) bond lengths are 1.73 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one K(2), four equivalent K(1), and one Fe(1) atom to form distorted edge-sharing OK5Fe octahedra. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(2), four equivalent K(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(2), three equivalent K(1), and one Fe(1) atom.