K2Cd3SnAs4 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one As(1), one As(4), and two equivalent As(3) atoms to form distorted CdAs4 tetrahedra that share corners with two equivalent Cd(1)As4 tetrahedra and corners with four equivalent Sn(1)As4 tetrahedra. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. In the third Cd site, Cd(3) is bonded in a 4-coordinate geometry to one As(2), one As(3), and two equivalent As(1) atoms. Sn(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form SnAs4 tetrahedra that share corners with two equivalent Sn(1)As4 tetrahedra and corners with four equivalent Cd(1)As4 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded to one K(1), two equivalent K(2), one Cd(1), one Cd(2), and two equivalent Cd(3) atoms to form distorted edge-sharing AsK3Cd4 pentagonal bipyramids. In the second As site, As(2) is bonded in a 7-coordinate geometry to one K(2), two equivalent K(1), one Cd(3), two equivalent Cd(2), and one Sn(1) atom. In the third As site, As(3) is bonded in a 7-coordinate geometry to one K(1), two equivalent K(2), one Cd(3), two equivalent Cd(1), and one Sn(1) atom. In the fourth As site, As(4) is bonded in a 7-coordinate geometry to one K(2), two equivalent K(1), one Cd(1), one Cd(2), and two equivalent Sn(1) atoms.
K2Cd3SnAs4 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms. The K(1)-As(1) bond length is 3.28 Å. The K(1)-As(3) bond length is 3.41 Å. Both K(1)-As(2) bond lengths are 3.48 Å. Both K(1)-As(4) bond lengths are 3.48 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms. The K(2)-As(2) bond length is 3.56 Å. The K(2)-As(4) bond length is 3.46 Å. Both K(2)-As(1) bond lengths are 3.33 Å. Both K(2)-As(3) bond lengths are 3.39 Å. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one As(1), one As(4), and two equivalent As(3) atoms to form distorted CdAs4 tetrahedra that share corners with two equivalent Cd(1)As4 tetrahedra and corners with four equivalent Sn(1)As4 tetrahedra. The Cd(1)-As(1) bond length is 2.83 Å. The Cd(1)-As(4) bond length is 2.85 Å. Both Cd(1)-As(3) bond lengths are 2.73 Å. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. The Cd(2)-As(1) bond length is 2.60 Å. The Cd(2)-As(4) bond length is 3.11 Å. Both Cd(2)-As(2) bond lengths are 2.67 Å. In the third Cd site, Cd(3) is bonded in a 4-coordinate geometry to one As(2), one As(3), and two equivalent As(1) atoms. The Cd(3)-As(2) bond length is 2.70 Å. The Cd(3)-As(3) bond length is 3.09 Å. Both Cd(3)-As(1) bond lengths are 2.62 Å. Sn(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form SnAs4 tetrahedra that share corners with two equivalent Sn(1)As4 tetrahedra and corners with four equivalent Cd(1)As4 tetrahedra. The Sn(1)-As(2) bond length is 2.65 Å. The Sn(1)-As(3) bond length is 2.65 Å. Both Sn(1)-As(4) bond lengths are 2.75 Å. There are four inequivalent As sites. In the first As site, As(1) is bonded to one K(1), two equivalent K(2), one Cd(1), one Cd(2), and two equivalent Cd(3) atoms to form distorted edge-sharing AsK3Cd4 pentagonal bipyramids. In the second As site, As(2) is bonded in a 7-coordinate geometry to one K(2), two equivalent K(1), one Cd(3), two equivalent Cd(2), and one Sn(1) atom. In the third As site, As(3) is bonded in a 7-coordinate geometry to one K(1), two equivalent K(2), one Cd(3), two equivalent Cd(1), and one Sn(1) atom. In the fourth As site, As(4) is bonded in a 7-coordinate geometry to one K(2), two equivalent K(1), one Cd(1), one Cd(2), and two equivalent Sn(1) atoms.