FeOOH crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 56°. H(1) is bonded in a distorted linear geometry to one O(1) and one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Fe(1) and one H(1) atom. In the second O site, O(2) is bonded to three equivalent Fe(1) and one H(1) atom to form a mixture of distorted corner and edge-sharing OFe3H tetrahedra.
FeOOH crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There is one shorter (2.09 Å) and two longer (2.13 Å) Fe(1)-O(1) bond lengths. There are two shorter (1.99 Å) and one longer (2.06 Å) Fe(1)-O(2) bond length. H(1) is bonded in a distorted linear geometry to one O(1) and one O(2) atom. The H(1)-O(1) bond length is 1.03 Å. The H(1)-O(2) bond length is 1.60 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Fe(1) and one H(1) atom. In the second O site, O(2) is bonded to three equivalent Fe(1) and one H(1) atom to form a mixture of distorted corner and edge-sharing OFe3H tetrahedra.