NaCd4As3 crystallizes in the trigonal R-3m space group. Na(1) is bonded to six equivalent As(1) atoms to form distorted NaAs6 octahedra that share corners with six equivalent Cd(2)As4 tetrahedra and edges with six equivalent Na(1)As6 octahedra. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded in a 3-coordinate geometry to one As(2) and three equivalent As(1) atoms. In the second Cd site, Cd(2) is bonded to one As(1) and three equivalent As(2) atoms to form CdAs4 tetrahedra that share corners with three equivalent Na(1)As6 octahedra, corners with nine equivalent Cd(2)As4 tetrahedra, and edges with three equivalent Cd(2)As4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent As sites. In the first As site, As(1) is bonded to three equivalent Na(1), one Cd(2), and three equivalent Cd(1) atoms to form a mixture of distorted corner and edge-sharing AsNa3Cd4 pentagonal bipyramids. In the second As site, As(2) is bonded in a distorted body-centered cubic geometry to two equivalent Cd(1) and six equivalent Cd(2) atoms.
NaCd4As3 crystallizes in the trigonal R-3m space group. Na(1) is bonded to six equivalent As(1) atoms to form distorted NaAs6 octahedra that share corners with six equivalent Cd(2)As4 tetrahedra and edges with six equivalent Na(1)As6 octahedra. All Na(1)-As(1) bond lengths are 3.19 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded in a 3-coordinate geometry to one As(2) and three equivalent As(1) atoms. The Cd(1)-As(2) bond length is 3.26 Å. All Cd(1)-As(1) bond lengths are 2.70 Å. In the second Cd site, Cd(2) is bonded to one As(1) and three equivalent As(2) atoms to form CdAs4 tetrahedra that share corners with three equivalent Na(1)As6 octahedra, corners with nine equivalent Cd(2)As4 tetrahedra, and edges with three equivalent Cd(2)As4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Cd(2)-As(1) bond length is 2.71 Å. All Cd(2)-As(2) bond lengths are 2.87 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to three equivalent Na(1), one Cd(2), and three equivalent Cd(1) atoms to form a mixture of distorted corner and edge-sharing AsNa3Cd4 pentagonal bipyramids. In the second As site, As(2) is bonded in a distorted body-centered cubic geometry to two equivalent Cd(1) and six equivalent Cd(2) atoms.