K3PSe16 crystallizes in the monoclinic C2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a q6 geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. In the second K site, K(2) is bonded in a 14-coordinate geometry to two P(1,1); two Se(3,3); two Se(4,4); two Se(5,5); two Se(7,7); and four Se(8,8) atoms. In the third K site, K(3) is bonded in a 14-coordinate geometry to two P(1,1); two Se(1,1); two Se(2,2); two Se(6,6); two Se(8,8); and four Se(7,7) atoms. In the fourth K site, K(1) is bonded in a q6 geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent K(2), two equivalent K(3), two equivalent Se(7), and two equivalent Se(8) atoms to form PK4Se4 tetrahedra that share corners with four equivalent P(1)K4Se4 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra; and corners with four Se(6,6)K2Se2 tetrahedra. In the second P site, P(1) is bonded to two equivalent K(2), two equivalent K(3), two equivalent Se(7), and two equivalent Se(8) atoms to form PK4Se4 tetrahedra that share corners with four equivalent P(1)K4Se4 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra; and corners with four Se(6,6)K2Se2 tetrahedra. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded to one K(1), one K(3), one Se(4), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(1,1)K2Se2 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with three Se(6,6)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(4)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the second Se site, Se(2) is bonded to one K(1), one K(3), one Se(3), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(3)K2Se2 tetrahedra;  a cornercorner with one Se(5)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(2,2)K2Se2 tetrahedra; corners with two equivalent Se(4)K2Se2 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(6,6)K2Se2 tetrahedra;  an edgeedge with one Se(3)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the third Se site, Se(3) is bonded to one K(1), one K(2), one Se(2), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(3,3)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(5,5)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the fourth Se site, Se(4) is bonded to one K(1), one K(2), one Se(1), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(1)K2Se2 tetrahedra;  a cornercorner with one Se(6)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(2)K2Se2 tetrahedra; corners with two Se(4,4)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the fifth Se site, Se(5) is bonded to one K(1), one K(2), one Se(2), and one Se(3) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(5,5)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(3)K2Se2 tetrahedra. In the sixth Se site, Se(6) is bonded to one K(1), one K(3), one Se(1), and one Se(4) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with two Se(6,6)K2Se2 tetrahedra; corners with three Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(4)K2Se2 tetrahedra. In the seventh Se site, Se(6) is bonded to one K(1), one K(3), one Se(1), and one Se(4) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with two Se(6,6)K2Se2 tetrahedra; corners with three Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(4)K2Se2 tetrahedra. In the eighth Se site, Se(2) is bonded to one K(1), one K(3), one Se(3), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(3)K2Se2 tetrahedra;  a cornercorner with one Se(5)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(2,2)K2Se2 tetrahedra; corners with two equivalent Se(4)K2Se2 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(6,6)K2Se2 tetrahedra;  an edgeedge with one Se(3)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the ninth Se site, Se(1) is bonded to one K(1), one K(3), one Se(4), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(1,1)K2Se2 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with three Se(6,6)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(4)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the tenth Se site, Se(3) is bonded to one K(1), one K(2), one Se(2), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(3,3)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(5,5)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the eleventh Se site, Se(4) is bonded to one K(1), one K(2), one Se(1), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(1)K2Se2 tetrahedra;  a cornercorner with one Se(6)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(2)K2Se2 tetrahedra; corners with two Se(4,4)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the twelfth Se site, Se(5) is bonded to one K(1), one K(2), one Se(2), and one Se(3) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(5,5)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(3)K2Se2 tetrahedra. In the thirteenth Se site, Se(7) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(3), and one P(1) atom. In the fourteenth Se site, Se(8) is bonded in a distorted single-bond geometry to one K(3), two equivalent K(2), and one P(1) atom. In the fifteenth Se site, Se(7) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(3), and one P(1) atom. In the sixteenth Se site, Se(8) is bonded in a distorted single-bond geometry to one K(3), two equivalent K(2), and one P(1) atom.
K3PSe16 crystallizes in the monoclinic C2 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a q6 geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. Both K(1)-Se(1) bond lengths are 3.76 Å. Both K(1)-Se(2) bond lengths are 3.77 Å. Both K(1)-Se(3) bond lengths are 3.77 Å. Both K(1)-Se(4) bond lengths are 3.76 Å. Both K(1)-Se(5) bond lengths are 3.77 Å. Both K(1)-Se(6) bond lengths are 3.77 Å. In the second K site, K(2) is bonded in a 14-coordinate geometry to two P(1,1); two Se(3,3); two Se(4,4); two Se(5,5); two Se(7,7); and four Se(8,8) atoms. Both K(2)-P(1,1) bond lengths are 3.60 Å. Both K(2)-Se(3,3) bond lengths are 3.77 Å. Both K(2)-Se(4,4) bond lengths are 3.77 Å. Both K(2)-Se(5,5) bond lengths are 3.77 Å. Both K(2)-Se(7,7) bond lengths are 3.54 Å. All K(2)-Se(8,8) bond lengths are 3.54 Å. In the third K site, K(3) is bonded in a 14-coordinate geometry to two P(1,1); two Se(1,1); two Se(2,2); two Se(6,6); two Se(8,8); and four Se(7,7) atoms. Both K(3)-P(1,1) bond lengths are 3.60 Å. Both K(3)-Se(1,1) bond lengths are 3.77 Å. Both K(3)-Se(2,2) bond lengths are 3.77 Å. Both K(3)-Se(6,6) bond lengths are 3.77 Å. There is one shorter (3.54 Å) and one longer (3.55 Å) K(3)-Se(8,8) bond length. There are three shorter (3.54 Å) and one longer (3.55 Å) K(3)-Se(7,7) bond length. In the fourth K site, K(1) is bonded in a q6 geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. Both K(1)-Se(1) bond lengths are 3.77 Å. Both K(1)-Se(2) bond lengths are 3.77 Å. Both K(1)-Se(3) bond lengths are 3.77 Å. Both K(1)-Se(4) bond lengths are 3.77 Å. Both K(1)-Se(5) bond lengths are 3.77 Å. Both K(1)-Se(6) bond lengths are 3.77 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to two equivalent K(2), two equivalent K(3), two equivalent Se(7), and two equivalent Se(8) atoms to form PK4Se4 tetrahedra that share corners with four equivalent P(1)K4Se4 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra; and corners with four Se(6,6)K2Se2 tetrahedra. Both P(1)-Se(7) bond lengths are 2.21 Å. Both P(1)-Se(8) bond lengths are 2.21 Å. In the second P site, P(1) is bonded to two equivalent K(2), two equivalent K(3), two equivalent Se(7), and two equivalent Se(8) atoms to form PK4Se4 tetrahedra that share corners with four equivalent P(1)K4Se4 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra; and corners with four Se(6,6)K2Se2 tetrahedra. Both P(1)-Se(7) bond lengths are 2.20 Å. Both P(1)-Se(8) bond lengths are 2.21 Å. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded to one K(1), one K(3), one Se(4), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(1,1)K2Se2 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with three Se(6,6)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(4)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. The Se(1)-Se(4) bond length is 2.39 Å. The Se(1)-Se(6) bond length is 2.39 Å. In the second Se site, Se(2) is bonded to one K(1), one K(3), one Se(3), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(3)K2Se2 tetrahedra;  a cornercorner with one Se(5)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(2,2)K2Se2 tetrahedra; corners with two equivalent Se(4)K2Se2 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(6,6)K2Se2 tetrahedra;  an edgeedge with one Se(3)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. The Se(2)-Se(3) bond length is 2.38 Å. The Se(2)-Se(5) bond length is 2.38 Å. In the third Se site, Se(3) is bonded to one K(1), one K(2), one Se(2), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(3,3)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(5,5)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. The Se(3)-Se(2) bond length is 2.38 Å. The Se(3)-Se(5) bond length is 2.39 Å. In the fourth Se site, Se(4) is bonded to one K(1), one K(2), one Se(1), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(1)K2Se2 tetrahedra;  a cornercorner with one Se(6)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(2)K2Se2 tetrahedra; corners with two Se(4,4)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. The Se(4)-Se(1) bond length is 2.39 Å. The Se(4)-Se(6) bond length is 2.38 Å. In the fifth Se site, Se(5) is bonded to one K(1), one K(2), one Se(2), and one Se(3) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(5,5)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(3)K2Se2 tetrahedra. The Se(5)-Se(2) bond length is 2.39 Å. The Se(5)-Se(3) bond length is 2.39 Å. In the sixth Se site, Se(6) is bonded to one K(1), one K(3), one Se(1), and one Se(4) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with two Se(6,6)K2Se2 tetrahedra; corners with three Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(4)K2Se2 tetrahedra. The Se(6)-Se(1) bond length is 2.38 Å. The Se(6)-Se(4) bond length is 2.39 Å. In the seventh Se site, Se(6) is bonded to one K(1), one K(3), one Se(1), and one Se(4) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with two Se(6,6)K2Se2 tetrahedra; corners with three Se(1,1)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(4)K2Se2 tetrahedra. In the eighth Se site, Se(2) is bonded to one K(1), one K(3), one Se(3), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(3)K2Se2 tetrahedra;  a cornercorner with one Se(5)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(2,2)K2Se2 tetrahedra; corners with two equivalent Se(4)K2Se2 tetrahedra; corners with four Se(1,1)K2Se2 tetrahedra; corners with four Se(6,6)K2Se2 tetrahedra;  an edgeedge with one Se(3)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the ninth Se site, Se(1) is bonded to one K(1), one K(3), one Se(4), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(4)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two Se(1,1)K2Se2 tetrahedra; corners with two equivalent Se(3)K2Se2 tetrahedra; corners with two equivalent Se(5)K2Se2 tetrahedra; corners with three Se(6,6)K2Se2 tetrahedra; corners with four Se(2,2)K2Se2 tetrahedra;  an edgeedge with one Se(4)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the tenth Se site, Se(3) is bonded to one K(1), one K(2), one Se(2), and one Se(5) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(3,3)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(5,5)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(5)K2Se2 tetrahedra. In the eleventh Se site, Se(4) is bonded to one K(1), one K(2), one Se(1), and one Se(6) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(1)K2Se2 tetrahedra;  a cornercorner with one Se(6)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(2)K2Se2 tetrahedra; corners with two Se(4,4)K2Se2 tetrahedra; corners with four Se(3,3)K2Se2 tetrahedra; corners with four Se(5,5)K2Se2 tetrahedra;  an edgeedge with one Se(1)K2Se2 tetrahedra; and  an edgeedge with one Se(6)K2Se2 tetrahedra. In the twelfth Se site, Se(5) is bonded to one K(1), one K(2), one Se(2), and one Se(3) atom to form distorted SeK2Se2 tetrahedra that share  a cornercorner with one Se(2)K2Se2 tetrahedra; corners with two P(1,1)K4Se4 tetrahedra; corners with two equivalent Se(1)K2Se2 tetrahedra; corners with two Se(5,5)K2Se2 tetrahedra; corners with two equivalent Se(6)K2Se2 tetrahedra; corners with three Se(3,3)K2Se2 tetrahedra; corners with four Se(4,4)K2Se2 tetrahedra;  an edgeedge with one Se(2)K2Se2 tetrahedra; and  an edgeedge with one Se(3)K2Se2 tetrahedra. In the thirteenth Se site, Se(7) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(3), and one P(1) atom. In the fourteenth Se site, Se(8) is bonded in a distorted single-bond geometry to one K(3), two equivalent K(2), and one P(1) atom. In the fifteenth Se site, Se(7) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(3), and one P(1) atom. In the sixteenth Se site, Se(8) is bonded in a distorted single-bond geometry to one K(3), two equivalent K(2), and one P(1) atom.