KLa(PSe3)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to one Se(4), one Se(5), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(6) atoms. La(1) is bonded in a 9-coordinate geometry to one Se(1), one Se(3), one Se(6), two equivalent Se(2), two equivalent Se(4), and two equivalent Se(5) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded in a distorted tetrahedral geometry to one P(2), one Se(1), one Se(2), and one Se(5) atom. In the second P site, P(2) is bonded to one P(1), one Se(3), one Se(4), and one Se(6) atom to form distorted PPSe3 tetrahedra that share  a cornercorner with one Se(1)K2LaP tetrahedra. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent K(1), one La(1), and one P(1) atom to form distorted SeK2LaP tetrahedra that share  a cornercorner with one P(2)PSe3 tetrahedra and corners with two equivalent Se(1)K2LaP tetrahedra. In the second Se site, Se(2) is bonded in a distorted T-shaped geometry to two equivalent La(1) and one P(1) atom. In the third Se site, Se(3) is bonded in a distorted see-saw-like geometry to two equivalent K(1), one La(1), and one P(2) atom. In the fourth Se site, Se(4) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent La(1), and one P(2) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to one K(1), two equivalent La(1), and one P(1) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one La(1), and one P(2) atom.
KLa(PSe3)2 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 8-coordinate geometry to one Se(4), one Se(5), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(6) atoms. The K(1)-Se(4) bond length is 3.39 Å. The K(1)-Se(5) bond length is 3.84 Å. There is one shorter (3.40 Å) and one longer (3.49 Å) K(1)-Se(1) bond length. There is one shorter (3.49 Å) and one longer (3.59 Å) K(1)-Se(3) bond length. There is one shorter (3.43 Å) and one longer (3.51 Å) K(1)-Se(6) bond length. La(1) is bonded in a 9-coordinate geometry to one Se(1), one Se(3), one Se(6), two equivalent Se(2), two equivalent Se(4), and two equivalent Se(5) atoms. The La(1)-Se(1) bond length is 3.17 Å. The La(1)-Se(3) bond length is 3.12 Å. The La(1)-Se(6) bond length is 3.38 Å. There is one shorter (3.18 Å) and one longer (3.22 Å) La(1)-Se(2) bond length. There is one shorter (3.15 Å) and one longer (3.41 Å) La(1)-Se(4) bond length. There is one shorter (3.22 Å) and one longer (3.28 Å) La(1)-Se(5) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded in a distorted tetrahedral geometry to one P(2), one Se(1), one Se(2), and one Se(5) atom. The P(1)-P(2) bond length is 2.26 Å. The P(1)-Se(1) bond length is 2.20 Å. The P(1)-Se(2) bond length is 2.23 Å. The P(1)-Se(5) bond length is 2.22 Å. In the second P site, P(2) is bonded to one P(1), one Se(3), one Se(4), and one Se(6) atom to form distorted PPSe3 tetrahedra that share  a cornercorner with one Se(1)K2LaP tetrahedra. The P(2)-Se(3) bond length is 2.21 Å. The P(2)-Se(4) bond length is 2.20 Å. The P(2)-Se(6) bond length is 2.19 Å. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent K(1), one La(1), and one P(1) atom to form distorted SeK2LaP tetrahedra that share  a cornercorner with one P(2)PSe3 tetrahedra and corners with two equivalent Se(1)K2LaP tetrahedra. In the second Se site, Se(2) is bonded in a distorted T-shaped geometry to two equivalent La(1) and one P(1) atom. In the third Se site, Se(3) is bonded in a distorted see-saw-like geometry to two equivalent K(1), one La(1), and one P(2) atom. In the fourth Se site, Se(4) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent La(1), and one P(2) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to one K(1), two equivalent La(1), and one P(1) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one La(1), and one P(2) atom.