FeO is Halite, Rock Salt-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-6°. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-6°. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(4) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second O site, O(2) is bonded to one Fe(1), one Fe(4), two equivalent Fe(2), and two equivalent Fe(3) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Fe(3), one Fe(4), two equivalent Fe(1), and two equivalent Fe(2) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.
FeO is Halite, Rock Salt-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-6°. The Fe(1)-O(2) bond length is 2.10 Å. The Fe(1)-O(4) bond length is 2.09 Å. There is one shorter (2.24 Å) and one longer (2.27 Å) Fe(1)-O(1) bond length. There is one shorter (2.26 Å) and one longer (2.27 Å) Fe(1)-O(3) bond length. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-6°. The Fe(2)-O(1) bond length is 2.25 Å. The Fe(2)-O(4) bond length is 2.26 Å. There is one shorter (2.13 Å) and one longer (2.23 Å) Fe(2)-O(2) bond length. There is one shorter (2.12 Å) and one longer (2.22 Å) Fe(2)-O(3) bond length. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. The Fe(3)-O(1) bond length is 2.10 Å. The Fe(3)-O(3) bond length is 2.09 Å. There is one shorter (2.25 Å) and one longer (2.27 Å) Fe(3)-O(2) bond length. There is one shorter (2.25 Å) and one longer (2.28 Å) Fe(3)-O(4) bond length. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. The Fe(4)-O(2) bond length is 2.25 Å. The Fe(4)-O(3) bond length is 2.26 Å. There is one shorter (2.16 Å) and one longer (2.19 Å) Fe(4)-O(1) bond length. There is one shorter (2.15 Å) and one longer (2.18 Å) Fe(4)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Fe(4) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second O site, O(2) is bonded to one Fe(1), one Fe(4), two equivalent Fe(2), and two equivalent Fe(3) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to one Fe(3), one Fe(4), two equivalent Fe(1), and two equivalent Fe(2) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.