KGe3As3 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Ge(3), one As(3), two equivalent As(2), and three equivalent As(1) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form GeAs4 tetrahedra that share corners with two equivalent Ge(1)As4 tetrahedra and corners with four equivalent Ge(2)GeAs3 tetrahedra. In the second Ge site, Ge(2) is bonded to one Ge(3), one As(1), and two equivalent As(3) atoms to form distorted GeGeAs3 tetrahedra that share corners with two equivalent As(2)K2Ge3 square pyramids, corners with two equivalent Ge(2)GeAs3 tetrahedra, and corners with four equivalent Ge(1)As4 tetrahedra. In the third Ge site, Ge(3) is bonded in a 5-coordinate geometry to two equivalent K(1), one Ge(2), and two equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to three equivalent K(1), one Ge(2), and two equivalent Ge(1) atoms to form distorted AsK3Ge3 octahedra that share corners with two equivalent As(2)K2Ge3 square pyramids, edges with four equivalent As(1)K3Ge3 octahedra, and edges with three equivalent As(2)K2Ge3 square pyramids. In the second As site, As(2) is bonded to two equivalent K(1), one Ge(1), and two equivalent Ge(3) atoms to form distorted AsK2Ge3 square pyramids that share corners with two equivalent As(1)K3Ge3 octahedra, corners with two equivalent Ge(2)GeAs3 tetrahedra, edges with three equivalent As(1)K3Ge3 octahedra, and edges with two equivalent As(2)K2Ge3 square pyramids. The corner-sharing octahedral tilt angles are 19°. In the third As site, As(3) is bonded in a rectangular see-saw-like geometry to one K(1), one Ge(1), and two equivalent Ge(2) atoms.
KGe3As3 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Ge(3), one As(3), two equivalent As(2), and three equivalent As(1) atoms. Both K(1)-Ge(3) bond lengths are 3.67 Å. The K(1)-As(3) bond length is 3.34 Å. Both K(1)-As(2) bond lengths are 3.45 Å. There are two shorter (3.71 Å) and one longer (3.74 Å) K(1)-As(1) bond length. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form GeAs4 tetrahedra that share corners with two equivalent Ge(1)As4 tetrahedra and corners with four equivalent Ge(2)GeAs3 tetrahedra. The Ge(1)-As(2) bond length is 2.45 Å. The Ge(1)-As(3) bond length is 2.46 Å. Both Ge(1)-As(1) bond lengths are 2.50 Å. In the second Ge site, Ge(2) is bonded to one Ge(3), one As(1), and two equivalent As(3) atoms to form distorted GeGeAs3 tetrahedra that share corners with two equivalent As(2)K2Ge3 square pyramids, corners with two equivalent Ge(2)GeAs3 tetrahedra, and corners with four equivalent Ge(1)As4 tetrahedra. The Ge(2)-Ge(3) bond length is 2.60 Å. The Ge(2)-As(1) bond length is 2.52 Å. Both Ge(2)-As(3) bond lengths are 2.52 Å. In the third Ge site, Ge(3) is bonded in a 5-coordinate geometry to two equivalent K(1), one Ge(2), and two equivalent As(2) atoms. Both Ge(3)-As(2) bond lengths are 2.57 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded to three equivalent K(1), one Ge(2), and two equivalent Ge(1) atoms to form distorted AsK3Ge3 octahedra that share corners with two equivalent As(2)K2Ge3 square pyramids, edges with four equivalent As(1)K3Ge3 octahedra, and edges with three equivalent As(2)K2Ge3 square pyramids. In the second As site, As(2) is bonded to two equivalent K(1), one Ge(1), and two equivalent Ge(3) atoms to form distorted AsK2Ge3 square pyramids that share corners with two equivalent As(1)K3Ge3 octahedra, corners with two equivalent Ge(2)GeAs3 tetrahedra, edges with three equivalent As(1)K3Ge3 octahedra, and edges with two equivalent As(2)K2Ge3 square pyramids. The corner-sharing octahedral tilt angles are 19°. In the third As site, As(3) is bonded in a rectangular see-saw-like geometry to one K(1), one Ge(1), and two equivalent Ge(2) atoms.