CeSiAs3 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 9-coordinate geometry to one As(6), two equivalent As(1), two equivalent As(2), two equivalent As(3), and two equivalent As(4) atoms. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to one As(5), two equivalent As(1), two equivalent As(2), two equivalent As(3), and two equivalent As(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one As(2), one As(6), and two equivalent As(5) atoms to form corner-sharing SiAs4 tetrahedra. In the second Si site, Si(2) is bonded to one As(1), one As(5), and two equivalent As(6) atoms to form corner-sharing SiAs4 tetrahedra. There are six inequivalent As sites. In the first As site, As(5) is bonded in a rectangular see-saw-like geometry to one Ce(2), one Si(2), and two equivalent Si(1) atoms. In the second As site, As(6) is bonded in a rectangular see-saw-like geometry to one Ce(1), one Si(1), and two equivalent Si(2) atoms. In the third As site, As(1) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing AsCe4Si trigonal bipyramids. In the fourth As site, As(2) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing AsCe4Si trigonal bipyramids. In the fifth As site, As(3) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), and three equivalent As(4) atoms. In the sixth As site, As(4) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), and three equivalent As(3) atoms.
CeSiAs3 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 9-coordinate geometry to one As(6), two equivalent As(1), two equivalent As(2), two equivalent As(3), and two equivalent As(4) atoms. The Ce(1)-As(6) bond length is 3.17 Å. There is one shorter (3.12 Å) and one longer (3.15 Å) Ce(1)-As(1) bond length. There is one shorter (3.05 Å) and one longer (3.10 Å) Ce(1)-As(2) bond length. There is one shorter (3.06 Å) and one longer (3.15 Å) Ce(1)-As(3) bond length. There is one shorter (3.09 Å) and one longer (3.12 Å) Ce(1)-As(4) bond length. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to one As(5), two equivalent As(1), two equivalent As(2), two equivalent As(3), and two equivalent As(4) atoms. The Ce(2)-As(5) bond length is 3.13 Å. There is one shorter (3.03 Å) and one longer (3.08 Å) Ce(2)-As(1) bond length. There is one shorter (3.03 Å) and one longer (3.12 Å) Ce(2)-As(2) bond length. There is one shorter (3.05 Å) and one longer (3.10 Å) Ce(2)-As(3) bond length. Both Ce(2)-As(4) bond lengths are 3.08 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one As(2), one As(6), and two equivalent As(5) atoms to form corner-sharing SiAs4 tetrahedra. The Si(1)-As(2) bond length is 2.36 Å. The Si(1)-As(6) bond length is 2.38 Å. There is one shorter (2.36 Å) and one longer (2.39 Å) Si(1)-As(5) bond length. In the second Si site, Si(2) is bonded to one As(1), one As(5), and two equivalent As(6) atoms to form corner-sharing SiAs4 tetrahedra. The Si(2)-As(1) bond length is 2.36 Å. The Si(2)-As(5) bond length is 2.39 Å. There is one shorter (2.36 Å) and one longer (2.40 Å) Si(2)-As(6) bond length. There are six inequivalent As sites. In the first As site, As(5) is bonded in a rectangular see-saw-like geometry to one Ce(2), one Si(2), and two equivalent Si(1) atoms. In the second As site, As(6) is bonded in a rectangular see-saw-like geometry to one Ce(1), one Si(1), and two equivalent Si(2) atoms. In the third As site, As(1) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing AsCe4Si trigonal bipyramids. In the fourth As site, As(2) is bonded to two equivalent Ce(1), two equivalent Ce(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing AsCe4Si trigonal bipyramids. In the fifth As site, As(3) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), and three equivalent As(4) atoms. There are a spread of As(3)-As(4) bond distances ranging from 2.74-3.05 Å. In the sixth As site, As(4) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), and three equivalent As(3) atoms.