Materials Data on KGeBiS4 by Materials Project
KBiGeS4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of K–S bond distances ranging from 3.22–3.57 Å. Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share a cornercorner with one BiS7 pentagonal bipyramid and edges with three equivalent BiS7 pentagonal bipyramids. There are a spread of Ge–S bond distances ranging from 2.21–2.25 Å. Bi3+ is bonded to seven S2- atoms to form distorted BiS7 pentagonal bipyramids that share corners with two equivalent BiS7 pentagonal bipyramids, a cornercorner with one GeS4 tetrahedra, edges with two equivalent BiS7 pentagonal bipyramids, and edges with three equivalent GeS4 tetrahedra. There are a spread of Bi–S bond distances ranging from 2.79–3.17 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Ge4+, and two equivalent Bi3+ atoms. In the second S2- site, S2- is bonded to three equivalent K1+, one Ge4+, and one Bi3+ atom to form a mixture of distorted corner and edge-sharing SK3GeBi trigonal bipyramids. In the third S2- site, S2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Ge4+, and two equivalent Bi3+ atoms. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to one K1+, one Ge4+, and two equivalent Bi3+ atoms.