KYGeS4 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 8-coordinate geometry to one S(4), two equivalent S(2), two equivalent S(3), and three equivalent S(1) atoms. Y(1) is bonded to one S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form distorted YS7 pentagonal bipyramids that share corners with two equivalent Y(1)S7 pentagonal bipyramids,  a cornercorner with one Ge(1)S4 tetrahedra, edges with two equivalent Y(1)S7 pentagonal bipyramids, and edges with three equivalent Ge(1)S4 tetrahedra. Ge(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form GeS4 tetrahedra that share  a cornercorner with one Y(1)S7 pentagonal bipyramid and edges with three equivalent Y(1)S7 pentagonal bipyramids. There are four inequivalent S sites. In the first S site, S(1) is bonded to three equivalent K(1), one Y(1), and one Ge(1) atom to form distorted SK3YGe trigonal bipyramids that share corners with five equivalent S(2)K2Y2Ge square pyramids, corners with two equivalent S(1)K3YGe trigonal bipyramids, edges with two equivalent S(2)K2Y2Ge square pyramids, and edges with two equivalent S(1)K3YGe trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent K(1), two equivalent Y(1), and one Ge(1) atom to form distorted SK2Y2Ge square pyramids that share corners with four equivalent S(2)K2Y2Ge square pyramids, corners with five equivalent S(1)K3YGe trigonal bipyramids, and edges with two equivalent S(1)K3YGe trigonal bipyramids. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent Y(1), and one Ge(1) atom. In the fourth S site, S(4) is bonded in a distorted see-saw-like geometry to one K(1), two equivalent Y(1), and one Ge(1) atom.
KYGeS4 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 8-coordinate geometry to one S(4), two equivalent S(2), two equivalent S(3), and three equivalent S(1) atoms. The K(1)-S(4) bond length is 3.22 Å. There is one shorter (3.41 Å) and one longer (3.46 Å) K(1)-S(2) bond length. There is one shorter (3.39 Å) and one longer (3.59 Å) K(1)-S(3) bond length. There are a spread of K(1)-S(1) bond distances ranging from 3.22-3.67 Å. Y(1) is bonded to one S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form distorted YS7 pentagonal bipyramids that share corners with two equivalent Y(1)S7 pentagonal bipyramids,  a cornercorner with one Ge(1)S4 tetrahedra, edges with two equivalent Y(1)S7 pentagonal bipyramids, and edges with three equivalent Ge(1)S4 tetrahedra. The Y(1)-S(1) bond length is 2.80 Å. There is one shorter (2.88 Å) and one longer (2.90 Å) Y(1)-S(2) bond length. Both Y(1)-S(3) bond lengths are 2.84 Å. There is one shorter (2.82 Å) and one longer (2.96 Å) Y(1)-S(4) bond length. Ge(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form GeS4 tetrahedra that share  a cornercorner with one Y(1)S7 pentagonal bipyramid and edges with three equivalent Y(1)S7 pentagonal bipyramids. The Ge(1)-S(1) bond length is 2.20 Å. The Ge(1)-S(2) bond length is 2.24 Å. The Ge(1)-S(3) bond length is 2.24 Å. The Ge(1)-S(4) bond length is 2.23 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to three equivalent K(1), one Y(1), and one Ge(1) atom to form distorted SK3YGe trigonal bipyramids that share corners with five equivalent S(2)K2Y2Ge square pyramids, corners with two equivalent S(1)K3YGe trigonal bipyramids, edges with two equivalent S(2)K2Y2Ge square pyramids, and edges with two equivalent S(1)K3YGe trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent K(1), two equivalent Y(1), and one Ge(1) atom to form distorted SK2Y2Ge square pyramids that share corners with four equivalent S(2)K2Y2Ge square pyramids, corners with five equivalent S(1)K3YGe trigonal bipyramids, and edges with two equivalent S(1)K3YGe trigonal bipyramids. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent Y(1), and one Ge(1) atom. In the fourth S site, S(4) is bonded in a distorted see-saw-like geometry to one K(1), two equivalent Y(1), and one Ge(1) atom.