CoAsS is pyrite-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to four equivalent As(1) and two equivalent S(1) atoms to form CoAs4S2 octahedra that share corners with four equivalent Co(1)As4S2 octahedra and corners with eight equivalent Co(2)As2S4 octahedra. The corner-sharing octahedral tilt angles range from 61-65°. In the second Co site, Co(2) is bonded to two equivalent As(1) and four equivalent S(1) atoms to form CoAs2S4 octahedra that share corners with four equivalent Co(2)As2S4 octahedra and corners with eight equivalent Co(1)As4S2 octahedra. The corner-sharing octahedral tilt angles range from 61-65°. As(1) is bonded in a 4-coordinate geometry to one Co(2), two equivalent Co(1), and one As(1) atom. S(1) is bonded in a 3-coordinate geometry to one Co(1) and two equivalent Co(2) atoms.
CoAsS is pyrite-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to four equivalent As(1) and two equivalent S(1) atoms to form CoAs4S2 octahedra that share corners with four equivalent Co(1)As4S2 octahedra and corners with eight equivalent Co(2)As2S4 octahedra. The corner-sharing octahedral tilt angles range from 61-65°. There are two shorter (2.32 Å) and two longer (2.34 Å) Co(1)-As(1) bond lengths. Both Co(1)-S(1) bond lengths are 2.25 Å. In the second Co site, Co(2) is bonded to two equivalent As(1) and four equivalent S(1) atoms to form CoAs2S4 octahedra that share corners with four equivalent Co(2)As2S4 octahedra and corners with eight equivalent Co(1)As4S2 octahedra. The corner-sharing octahedral tilt angles range from 61-65°. Both Co(2)-As(1) bond lengths are 2.36 Å. All Co(2)-S(1) bond lengths are 2.35 Å. As(1) is bonded in a 4-coordinate geometry to one Co(2), two equivalent Co(1), and one As(1) atom. The As(1)-As(1) bond length is 2.39 Å. S(1) is bonded in a 3-coordinate geometry to one Co(1) and two equivalent Co(2) atoms.