FeCl2(H2O)4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded in a distorted octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent Cl(1) atoms. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) and one Cl(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) and one Cl(1) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(2) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Fe(1), one H(3), and one H(4) atom. Cl(1) is bonded in a 3-coordinate geometry to one Fe(1), one H(3), and one H(4) atom.
FeCl2(H2O)4 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded in a distorted octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent Cl(1) atoms. Both Fe(1)-O(1) bond lengths are 2.21 Å. Both Fe(1)-O(2) bond lengths are 2.12 Å. Both Fe(1)-Cl(1) bond lengths are 2.53 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. The H(2)-O(1) bond length is 0.98 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) and one Cl(1) atom. The H(3)-O(2) bond length is 1.00 Å. The H(3)-Cl(1) bond length is 2.10 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) and one Cl(1) atom. The H(4)-O(2) bond length is 0.99 Å. The H(4)-Cl(1) bond length is 2.14 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Fe(1), one H(1), and one H(2) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Fe(1), one H(3), and one H(4) atom. Cl(1) is bonded in a 3-coordinate geometry to one Fe(1), one H(3), and one H(4) atom.