K4Ba2SnAs4 crystallizes in the monoclinic Cc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one Sn(1), one As(1), one As(2), one As(3), and two equivalent As(4) atoms. In the second K site, K(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(3) atoms. In the third K site, K(3) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one As(1), one As(2), one As(3), and one As(4) atom. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to one Sn(1), one As(1), one As(2), one As(3), and two equivalent As(4) atoms. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one As(1), two equivalent As(2), and two equivalent As(3) atoms. Sn(1) is bonded in a distorted tetrahedral geometry to one K(1), one Ba(1), one As(1), one As(2), one As(3), and one As(4) atom. There are four inequivalent As sites. In the first As site, As(4) is bonded in a 8-coordinate geometry to one K(2), one K(3), one K(4), two equivalent K(1), two equivalent Ba(1), and one Sn(1) atom. In the second As site, As(1) is bonded in a 7-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Ba(1), one Ba(2), and one Sn(1) atom. In the third As site, As(2) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(3), one Ba(1), two equivalent Ba(2), and one Sn(1) atom. In the fourth As site, As(3) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(2), one Ba(1), two equivalent Ba(2), and one Sn(1) atom.
K4Ba2SnAs4 crystallizes in the monoclinic Cc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one Sn(1), one As(1), one As(2), one As(3), and two equivalent As(4) atoms. The K(1)-Sn(1) bond length is 3.66 Å. The K(1)-As(1) bond length is 3.47 Å. The K(1)-As(2) bond length is 3.74 Å. The K(1)-As(3) bond length is 3.48 Å. There is one shorter (3.45 Å) and one longer (3.70 Å) K(1)-As(4) bond length. In the second K site, K(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(3) atoms. The K(2)-As(1) bond length is 3.57 Å. The K(2)-As(4) bond length is 3.29 Å. There is one shorter (3.31 Å) and one longer (3.36 Å) K(2)-As(3) bond length. In the third K site, K(3) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. The K(3)-As(1) bond length is 3.53 Å. The K(3)-As(4) bond length is 3.27 Å. There is one shorter (3.32 Å) and one longer (3.45 Å) K(3)-As(2) bond length. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one As(1), one As(2), one As(3), and one As(4) atom. The K(4)-As(1) bond length is 3.61 Å. The K(4)-As(2) bond length is 3.40 Å. The K(4)-As(3) bond length is 3.38 Å. The K(4)-As(4) bond length is 3.38 Å. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to one Sn(1), one As(1), one As(2), one As(3), and two equivalent As(4) atoms. The Ba(1)-Sn(1) bond length is 3.71 Å. The Ba(1)-As(1) bond length is 3.51 Å. The Ba(1)-As(2) bond length is 3.39 Å. The Ba(1)-As(3) bond length is 3.62 Å. There is one shorter (3.37 Å) and one longer (3.64 Å) Ba(1)-As(4) bond length. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one As(1), two equivalent As(2), and two equivalent As(3) atoms. The Ba(2)-As(1) bond length is 3.36 Å. There is one shorter (3.36 Å) and one longer (3.66 Å) Ba(2)-As(2) bond length. There is one shorter (3.36 Å) and one longer (3.58 Å) Ba(2)-As(3) bond length. Sn(1) is bonded in a distorted tetrahedral geometry to one K(1), one Ba(1), one As(1), one As(2), one As(3), and one As(4) atom. The Sn(1)-As(1) bond length is 2.71 Å. The Sn(1)-As(2) bond length is 2.69 Å. The Sn(1)-As(3) bond length is 2.71 Å. The Sn(1)-As(4) bond length is 2.67 Å. There are four inequivalent As sites. In the first As site, As(4) is bonded in a 8-coordinate geometry to one K(2), one K(3), one K(4), two equivalent K(1), two equivalent Ba(1), and one Sn(1) atom. In the second As site, As(1) is bonded in a 7-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Ba(1), one Ba(2), and one Sn(1) atom. In the third As site, As(2) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(3), one Ba(1), two equivalent Ba(2), and one Sn(1) atom. In the fourth As site, As(3) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(2), one Ba(1), two equivalent Ba(2), and one Sn(1) atom.