Ca(FeS2)2 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Ca(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CaS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Ca(1)S6 octahedra, and edges with four equivalent Fe(2)S6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with six equivalent Ca(1)S6 octahedra and corners with six equivalent Fe(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 45-66°. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Fe(2)S6 octahedra, and edges with four equivalent Ca(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Fe(1), and one Fe(2) atom.
Ca(FeS2)2 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Ca(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CaS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Ca(1)S6 octahedra, and edges with four equivalent Fe(2)S6 octahedra. Both Ca(1)-S(1) bond lengths are 2.70 Å. All Ca(1)-S(2) bond lengths are 2.67 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with six equivalent Ca(1)S6 octahedra and corners with six equivalent Fe(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 45-66°. Both Fe(1)-S(1) bond lengths are 2.41 Å. Both Fe(1)-S(2) bond lengths are 2.20 Å. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Fe(2)S6 octahedra, and edges with four equivalent Ca(1)S6 octahedra. Both Fe(2)-S(2) bond lengths are 2.33 Å. All Fe(2)-S(1) bond lengths are 2.37 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Fe(1), and one Fe(2) atom.