K2Ni3S4 crystallizes in the triclinic P1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(5), one S(7), three equivalent S(1), and three equivalent S(4) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one S(6), one S(8), three equivalent S(2), and three equivalent S(3) atoms. In the third K site, K(3) is bonded in a 8-coordinate geometry to one S(1), one S(4), three equivalent S(5), and three equivalent S(7) atoms. In the fourth K site, K(4) is bonded in a 8-coordinate geometry to one S(2), one S(3), three equivalent S(6), and three equivalent S(8) atoms. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. In the second Ni site, Ni(2) is bonded in a square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. In the third Ni site, Ni(3) is bonded in a square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. In the fourth Ni site, Ni(4) is bonded in a distorted square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. In the fifth Ni site, Ni(5) is bonded in a square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. In the sixth Ni site, Ni(6) is bonded in a square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one K(3), three equivalent K(1), one Ni(1), one Ni(2), and one Ni(5) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to one K(4), three equivalent K(2), one Ni(1), one Ni(2), and one Ni(5) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one K(4), three equivalent K(2), one Ni(1), one Ni(2), and one Ni(5) atom. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to one K(3), three equivalent K(1), one Ni(1), one Ni(2), and one Ni(5) atom. In the fifth S site, S(5) is bonded in a 3-coordinate geometry to one K(1), three equivalent K(3), one Ni(3), one Ni(4), and one Ni(6) atom. In the sixth S site, S(6) is bonded in a 3-coordinate geometry to one K(2), three equivalent K(4), one Ni(3), one Ni(4), and one Ni(6) atom. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one K(1), three equivalent K(3), one Ni(3), one Ni(4), and one Ni(6) atom. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one K(2), three equivalent K(4), one Ni(3), one Ni(4), and one Ni(6) atom.
K2Ni3S4 crystallizes in the triclinic P1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(5), one S(7), three equivalent S(1), and three equivalent S(4) atoms. The K(1)-S(5) bond length is 3.45 Å. The K(1)-S(7) bond length is 3.47 Å. There are two shorter (3.38 Å) and one longer (3.43 Å) K(1)-S(1) bond length. There are a spread of K(1)-S(4) bond distances ranging from 3.37-3.45 Å. In the second K site, K(2) is bonded in a 8-coordinate geometry to one S(6), one S(8), three equivalent S(2), and three equivalent S(3) atoms. The K(2)-S(6) bond length is 3.50 Å. The K(2)-S(8) bond length is 3.55 Å. There are a spread of K(2)-S(2) bond distances ranging from 3.39-3.43 Å. There are a spread of K(2)-S(3) bond distances ranging from 3.31-3.46 Å. In the third K site, K(3) is bonded in a 8-coordinate geometry to one S(1), one S(4), three equivalent S(5), and three equivalent S(7) atoms. The K(3)-S(1) bond length is 3.48 Å. The K(3)-S(4) bond length is 3.55 Å. There are a spread of K(3)-S(5) bond distances ranging from 3.34-3.46 Å. There are a spread of K(3)-S(7) bond distances ranging from 3.29-3.47 Å. In the fourth K site, K(4) is bonded in a 8-coordinate geometry to one S(2), one S(3), three equivalent S(6), and three equivalent S(8) atoms. The K(4)-S(2) bond length is 3.50 Å. The K(4)-S(3) bond length is 3.51 Å. There are two shorter (3.40 Å) and one longer (3.42 Å) K(4)-S(6) bond length. There are a spread of K(4)-S(8) bond distances ranging from 3.30-3.48 Å. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a distorted square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. The Ni(1)-S(1) bond length is 2.22 Å. The Ni(1)-S(2) bond length is 2.22 Å. The Ni(1)-S(3) bond length is 2.28 Å. The Ni(1)-S(4) bond length is 2.18 Å. In the second Ni site, Ni(2) is bonded in a square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. The Ni(2)-S(1) bond length is 2.30 Å. The Ni(2)-S(2) bond length is 2.11 Å. The Ni(2)-S(3) bond length is 2.24 Å. The Ni(2)-S(4) bond length is 2.17 Å. In the third Ni site, Ni(3) is bonded in a square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. The Ni(3)-S(5) bond length is 2.20 Å. The Ni(3)-S(6) bond length is 2.22 Å. The Ni(3)-S(7) bond length is 2.21 Å. The Ni(3)-S(8) bond length is 2.17 Å. In the fourth Ni site, Ni(4) is bonded in a distorted square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. The Ni(4)-S(5) bond length is 2.30 Å. The Ni(4)-S(6) bond length is 2.13 Å. The Ni(4)-S(7) bond length is 2.27 Å. The Ni(4)-S(8) bond length is 2.17 Å. In the fifth Ni site, Ni(5) is bonded in a square co-planar geometry to one S(1), one S(2), one S(3), and one S(4) atom. The Ni(5)-S(1) bond length is 2.24 Å. The Ni(5)-S(2) bond length is 2.16 Å. The Ni(5)-S(3) bond length is 2.17 Å. The Ni(5)-S(4) bond length is 2.25 Å. In the sixth Ni site, Ni(6) is bonded in a square co-planar geometry to one S(5), one S(6), one S(7), and one S(8) atom. The Ni(6)-S(5) bond length is 2.19 Å. The Ni(6)-S(6) bond length is 2.22 Å. The Ni(6)-S(7) bond length is 2.21 Å. The Ni(6)-S(8) bond length is 2.15 Å. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one K(3), three equivalent K(1), one Ni(1), one Ni(2), and one Ni(5) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to one K(4), three equivalent K(2), one Ni(1), one Ni(2), and one Ni(5) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one K(4), three equivalent K(2), one Ni(1), one Ni(2), and one Ni(5) atom. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to one K(3), three equivalent K(1), one Ni(1), one Ni(2), and one Ni(5) atom. In the fifth S site, S(5) is bonded in a 3-coordinate geometry to one K(1), three equivalent K(3), one Ni(3), one Ni(4), and one Ni(6) atom. In the sixth S site, S(6) is bonded in a 3-coordinate geometry to one K(2), three equivalent K(4), one Ni(3), one Ni(4), and one Ni(6) atom. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one K(1), three equivalent K(3), one Ni(3), one Ni(4), and one Ni(6) atom. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one K(2), three equivalent K(4), one Ni(3), one Ni(4), and one Ni(6) atom.