K3AlAs2 is alpha Pu-derived structured and crystallizes in the triclinic P-1 space group. There are twelve inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent Al(2), one As(1), one As(3), one As(5), one As(8), and two equivalent As(2) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one K(10), two equivalent Al(1), one As(1), one As(3), one As(6), one As(7), and two equivalent As(4) atoms. In the third K site, K(3) is bonded in a 4-coordinate geometry to one As(2), one As(3), one As(4), and one As(5) atom. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one K(10), one As(2), one As(3), one As(4), and one As(5) atom. In the fifth K site, K(5) is bonded in a 4-coordinate geometry to one K(10), one As(1), one As(4), one As(6), and one As(7) atom. In the sixth K site, K(6) is bonded in a distorted see-saw-like geometry to one As(1), one As(4), and two equivalent As(2) atoms. In the seventh K site, K(7) is bonded to one K(10), one As(1), one As(2), one As(6), and one As(8) atom to form distorted KKAs4 trigonal pyramids that share  a cornercorner with one Al(2)K3As4 tetrahedra,  an edgeedge with one Al(1)K3As4 tetrahedra, and  a faceface with one Al(2)K3As4 tetrahedra. In the eighth K site, K(8) is bonded in a 6-coordinate geometry to one Al(3), one Al(4), one As(3), one As(6), one As(7), and one As(8) atom. In the ninth K site, K(9) is bonded in a 6-coordinate geometry to one Al(3), one Al(4), one As(1), one As(5), one As(7), and one As(8) atom. In the tenth K site, K(10) is bonded in a 13-coordinate geometry to one K(10), one K(2), one K(4), one K(5), one K(7), one Al(1), one Al(2), one As(1), one As(6), two equivalent As(3), and two equivalent As(4) atoms. In the eleventh K site, K(11) is bonded in a 4-coordinate geometry to one As(5), one As(6), and two equivalent As(8) atoms. In the twelfth K site, K(12) is bonded in a 4-coordinate geometry to one As(5), one As(6), and two equivalent As(7) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one K(10), two equivalent K(2), one As(1), one As(3), and two equivalent As(4) atoms to form distorted AlK3As4 tetrahedra that share  an edgeedge with one K(7)KAs4 trigonal pyramid,  a faceface with one Al(1)K3As4 tetrahedra, and  a faceface with one Al(2)K3As4 tetrahedra. In the second Al site, Al(2) is bonded to one K(10), two equivalent K(1), one As(1), one As(3), and two equivalent As(2) atoms to form distorted AlK3As4 tetrahedra that share  a cornercorner with one K(7)KAs4 trigonal pyramid,  a faceface with one Al(1)K3As4 tetrahedra,  a faceface with one Al(2)K3As4 tetrahedra, and  a faceface with one K(7)KAs4 trigonal pyramid. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to one K(8), one K(9), one As(5), one As(7), and one As(8) atom. In the fourth Al site, Al(4) is bonded in a distorted trigonal planar geometry to one K(8), one K(9), one As(6), one As(7), and one As(8) atom. There are eight inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(5), one K(6), one K(7), one K(9), one Al(1), and one Al(2) atom. In the second As site, As(2) is bonded in a 9-coordinate geometry to one K(3), one K(4), one K(7), two equivalent K(1), two equivalent K(6), and two equivalent Al(2) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one K(8), two equivalent K(10), one Al(1), and one Al(2) atom. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to one K(3), one K(4), one K(5), one K(6), two equivalent K(10), two equivalent K(2), and two equivalent Al(1) atoms. In the fifth As site, As(5) is bonded in a 7-coordinate geometry to one K(1), one K(11), one K(12), one K(3), one K(4), one K(9), and one Al(3) atom. In the sixth As site, As(6) is bonded in a 8-coordinate geometry to one K(10), one K(11), one K(12), one K(2), one K(5), one K(7), one K(8), and one Al(4) atom. In the seventh As site, As(7) is bonded in a 8-coordinate geometry to one K(2), one K(5), one K(8), one K(9), two equivalent K(12), one Al(3), and one Al(4) atom. In the eighth As site, As(8) is bonded in a 8-coordinate geometry to one K(1), one K(7), one K(8), one K(9), two equivalent K(11), one Al(3), and one Al(4) atom.
K3AlAs2 is alpha Pu-derived structured and crystallizes in the triclinic P-1 space group. There are twelve inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent Al(2), one As(1), one As(3), one As(5), one As(8), and two equivalent As(2) atoms. There is one shorter (3.36 Å) and one longer (3.40 Å) K(1)-Al(2) bond length. The K(1)-As(1) bond length is 3.41 Å. The K(1)-As(3) bond length is 3.58 Å. The K(1)-As(5) bond length is 3.51 Å. The K(1)-As(8) bond length is 3.28 Å. There is one shorter (3.47 Å) and one longer (3.50 Å) K(1)-As(2) bond length. In the second K site, K(2) is bonded in a 8-coordinate geometry to one K(10), two equivalent Al(1), one As(1), one As(3), one As(6), one As(7), and two equivalent As(4) atoms. The K(2)-K(10) bond length is 3.78 Å. There is one shorter (3.42 Å) and one longer (3.51 Å) K(2)-Al(1) bond length. The K(2)-As(1) bond length is 3.58 Å. The K(2)-As(3) bond length is 3.35 Å. The K(2)-As(6) bond length is 3.58 Å. The K(2)-As(7) bond length is 3.68 Å. There is one shorter (3.46 Å) and one longer (3.75 Å) K(2)-As(4) bond length. In the third K site, K(3) is bonded in a 4-coordinate geometry to one As(2), one As(3), one As(4), and one As(5) atom. The K(3)-As(2) bond length is 3.31 Å. The K(3)-As(3) bond length is 3.24 Å. The K(3)-As(4) bond length is 3.46 Å. The K(3)-As(5) bond length is 3.44 Å. In the fourth K site, K(4) is bonded in a 4-coordinate geometry to one K(10), one As(2), one As(3), one As(4), and one As(5) atom. The K(4)-K(10) bond length is 3.81 Å. The K(4)-As(2) bond length is 3.35 Å. The K(4)-As(3) bond length is 3.15 Å. The K(4)-As(4) bond length is 3.18 Å. The K(4)-As(5) bond length is 3.40 Å. In the fifth K site, K(5) is bonded in a 4-coordinate geometry to one K(10), one As(1), one As(4), one As(6), and one As(7) atom. The K(5)-K(10) bond length is 3.52 Å. The K(5)-As(1) bond length is 3.28 Å. The K(5)-As(4) bond length is 3.47 Å. The K(5)-As(6) bond length is 3.31 Å. The K(5)-As(7) bond length is 3.43 Å. In the sixth K site, K(6) is bonded in a distorted see-saw-like geometry to one As(1), one As(4), and two equivalent As(2) atoms. The K(6)-As(1) bond length is 3.29 Å. The K(6)-As(4) bond length is 3.56 Å. There is one shorter (3.32 Å) and one longer (3.66 Å) K(6)-As(2) bond length. In the seventh K site, K(7) is bonded to one K(10), one As(1), one As(2), one As(6), and one As(8) atom to form distorted KKAs4 trigonal pyramids that share  a cornercorner with one Al(2)K3As4 tetrahedra,  an edgeedge with one Al(1)K3As4 tetrahedra, and  a faceface with one Al(2)K3As4 tetrahedra. The K(7)-K(10) bond length is 3.69 Å. The K(7)-As(1) bond length is 3.39 Å. The K(7)-As(2) bond length is 3.33 Å. The K(7)-As(6) bond length is 3.23 Å. The K(7)-As(8) bond length is 3.41 Å. In the eighth K site, K(8) is bonded in a 6-coordinate geometry to one Al(3), one Al(4), one As(3), one As(6), one As(7), and one As(8) atom. The K(8)-Al(3) bond length is 3.48 Å. The K(8)-Al(4) bond length is 3.59 Å. The K(8)-As(3) bond length is 3.42 Å. The K(8)-As(6) bond length is 3.40 Å. The K(8)-As(7) bond length is 3.75 Å. The K(8)-As(8) bond length is 3.82 Å. In the ninth K site, K(9) is bonded in a 6-coordinate geometry to one Al(3), one Al(4), one As(1), one As(5), one As(7), and one As(8) atom. The K(9)-Al(3) bond length is 3.59 Å. The K(9)-Al(4) bond length is 3.64 Å. The K(9)-As(1) bond length is 3.31 Å. The K(9)-As(5) bond length is 3.56 Å. The K(9)-As(7) bond length is 3.62 Å. The K(9)-As(8) bond length is 3.53 Å. In the tenth K site, K(10) is bonded in a 13-coordinate geometry to one K(10), one K(2), one K(4), one K(5), one K(7), one Al(1), one Al(2), one As(1), one As(6), two equivalent As(3), and two equivalent As(4) atoms. The K(10)-K(10) bond length is 3.29 Å. The K(10)-Al(1) bond length is 3.68 Å. The K(10)-Al(2) bond length is 3.85 Å. The K(10)-As(1) bond length is 3.51 Å. The K(10)-As(6) bond length is 3.79 Å. There is one shorter (3.55 Å) and one longer (3.84 Å) K(10)-As(3) bond length. There is one shorter (3.59 Å) and one longer (3.97 Å) K(10)-As(4) bond length. In the eleventh K site, K(11) is bonded in a 4-coordinate geometry to one As(5), one As(6), and two equivalent As(8) atoms. The K(11)-As(5) bond length is 3.30 Å. The K(11)-As(6) bond length is 3.51 Å. There is one shorter (3.42 Å) and one longer (3.53 Å) K(11)-As(8) bond length. In the twelfth K site, K(12) is bonded in a 4-coordinate geometry to one As(5), one As(6), and two equivalent As(7) atoms. The K(12)-As(5) bond length is 3.37 Å. The K(12)-As(6) bond length is 3.47 Å. There is one shorter (3.34 Å) and one longer (3.67 Å) K(12)-As(7) bond length. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one K(10), two equivalent K(2), one As(1), one As(3), and two equivalent As(4) atoms to form distorted AlK3As4 tetrahedra that share  an edgeedge with one K(7)KAs4 trigonal pyramid,  a faceface with one Al(1)K3As4 tetrahedra, and  a faceface with one Al(2)K3As4 tetrahedra. The Al(1)-As(1) bond length is 2.51 Å. The Al(1)-As(3) bond length is 2.52 Å. There is one shorter (2.52 Å) and one longer (2.54 Å) Al(1)-As(4) bond length. In the second Al site, Al(2) is bonded to one K(10), two equivalent K(1), one As(1), one As(3), and two equivalent As(2) atoms to form distorted AlK3As4 tetrahedra that share  a cornercorner with one K(7)KAs4 trigonal pyramid,  a faceface with one Al(1)K3As4 tetrahedra,  a faceface with one Al(2)K3As4 tetrahedra, and  a faceface with one K(7)KAs4 trigonal pyramid. The Al(2)-As(1) bond length is 2.52 Å. The Al(2)-As(3) bond length is 2.53 Å. There is one shorter (2.53 Å) and one longer (2.58 Å) Al(2)-As(2) bond length. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to one K(8), one K(9), one As(5), one As(7), and one As(8) atom. The Al(3)-As(5) bond length is 2.34 Å. The Al(3)-As(7) bond length is 2.45 Å. The Al(3)-As(8) bond length is 2.46 Å. In the fourth Al site, Al(4) is bonded in a distorted trigonal planar geometry to one K(8), one K(9), one As(6), one As(7), and one As(8) atom. The Al(4)-As(6) bond length is 2.33 Å. The Al(4)-As(7) bond length is 2.46 Å. The Al(4)-As(8) bond length is 2.41 Å. There are eight inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(5), one K(6), one K(7), one K(9), one Al(1), and one Al(2) atom. In the second As site, As(2) is bonded in a 9-coordinate geometry to one K(3), one K(4), one K(7), two equivalent K(1), two equivalent K(6), and two equivalent Al(2) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one K(8), two equivalent K(10), one Al(1), and one Al(2) atom. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to one K(3), one K(4), one K(5), one K(6), two equivalent K(10), two equivalent K(2), and two equivalent Al(1) atoms. In the fifth As site, As(5) is bonded in a 7-coordinate geometry to one K(1), one K(11), one K(12), one K(3), one K(4), one K(9), and one Al(3) atom. In the sixth As site, As(6) is bonded in a 8-coordinate geometry to one K(10), one K(11), one K(12), one K(2), one K(5), one K(7), one K(8), and one Al(4) atom. In the seventh As site, As(7) is bonded in a 8-coordinate geometry to one K(2), one K(5), one K(8), one K(9), two equivalent K(12), one Al(3), and one Al(4) atom. In the eighth As site, As(8) is bonded in a 8-coordinate geometry to one K(1), one K(7), one K(8), one K(9), two equivalent K(11), one Al(3), and one Al(4) atom.