Cr12C3As4N crystallizes in the monoclinic C2/m space group. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to two equivalent C(1), one As(2), and two equivalent As(1) atoms. In the second Cr site, Cr(2) is bonded in a 5-coordinate geometry to two equivalent C(1), one As(1), and two equivalent As(2) atoms. In the third Cr site, Cr(3) is bonded in a 5-coordinate geometry to two equivalent C(2) and three equivalent As(1) atoms. In the fourth Cr site, Cr(4) is bonded in a distorted water-like geometry to three equivalent As(2) and two equivalent N(1) atoms. In the fifth Cr site, Cr(5) is bonded in a distorted bent 150 degrees geometry to one C(1), one C(2), and two equivalent As(1) atoms. In the sixth Cr site, Cr(6) is bonded in a distorted bent 150 degrees geometry to one C(1), two equivalent As(2), and one N(1) atom. There are two inequivalent C sites. In the first C site, C(1) is bonded to one Cr(5), one Cr(6), two equivalent Cr(1), and two equivalent Cr(2) atoms to form CCr6 octahedra that share  a cornercorner with one C(2)Cr6 octahedra,  a cornercorner with one N(1)Cr6 octahedra, and edges with two equivalent C(1)Cr6 octahedra. The corner-sharing octahedral tilt angles are 25°. In the second C site, C(2) is bonded to two equivalent Cr(5) and four equivalent Cr(3) atoms to form a mixture of corner and edge-sharing CCr6 octahedra. The corner-sharing octahedral tilt angles are 25°. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Cr(2), two equivalent Cr(1), two equivalent Cr(5), and three equivalent Cr(3) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Cr(1), two equivalent Cr(2), two equivalent Cr(6), and three equivalent Cr(4) atoms. N(1) is bonded to two equivalent Cr(6) and four equivalent Cr(4) atoms to form NCr6 octahedra that share corners with two equivalent C(1)Cr6 octahedra and edges with two equivalent N(1)Cr6 octahedra. The corner-sharing octahedral tilt angles are 25°.
Cr12C3As4N crystallizes in the monoclinic C2/m space group. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to two equivalent C(1), one As(2), and two equivalent As(1) atoms. Both Cr(1)-C(1) bond lengths are 2.00 Å. The Cr(1)-As(2) bond length is 2.52 Å. Both Cr(1)-As(1) bond lengths are 2.54 Å. In the second Cr site, Cr(2) is bonded in a 5-coordinate geometry to two equivalent C(1), one As(1), and two equivalent As(2) atoms. Both Cr(2)-C(1) bond lengths are 2.00 Å. The Cr(2)-As(1) bond length is 2.52 Å. Both Cr(2)-As(2) bond lengths are 2.53 Å. In the third Cr site, Cr(3) is bonded in a 5-coordinate geometry to two equivalent C(2) and three equivalent As(1) atoms. Both Cr(3)-C(2) bond lengths are 1.99 Å. There are two shorter (2.53 Å) and one longer (2.54 Å) Cr(3)-As(1) bond length. In the fourth Cr site, Cr(4) is bonded in a distorted water-like geometry to three equivalent As(2) and two equivalent N(1) atoms. There is one shorter (2.53 Å) and two longer (2.55 Å) Cr(4)-As(2) bond lengths. Both Cr(4)-N(1) bond lengths are 1.98 Å. In the fifth Cr site, Cr(5) is bonded in a distorted bent 150 degrees geometry to one C(1), one C(2), and two equivalent As(1) atoms. The Cr(5)-C(1) bond length is 1.90 Å. The Cr(5)-C(2) bond length is 1.91 Å. Both Cr(5)-As(1) bond lengths are 2.53 Å. In the sixth Cr site, Cr(6) is bonded in a distorted bent 150 degrees geometry to one C(1), two equivalent As(2), and one N(1) atom. The Cr(6)-C(1) bond length is 1.91 Å. Both Cr(6)-As(2) bond lengths are 2.54 Å. The Cr(6)-N(1) bond length is 1.88 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded to one Cr(5), one Cr(6), two equivalent Cr(1), and two equivalent Cr(2) atoms to form CCr6 octahedra that share  a cornercorner with one C(2)Cr6 octahedra,  a cornercorner with one N(1)Cr6 octahedra, and edges with two equivalent C(1)Cr6 octahedra. The corner-sharing octahedral tilt angles are 25°. In the second C site, C(2) is bonded to two equivalent Cr(5) and four equivalent Cr(3) atoms to form a mixture of corner and edge-sharing CCr6 octahedra. The corner-sharing octahedral tilt angles are 25°. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Cr(2), two equivalent Cr(1), two equivalent Cr(5), and three equivalent Cr(3) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Cr(1), two equivalent Cr(2), two equivalent Cr(6), and three equivalent Cr(4) atoms. N(1) is bonded to two equivalent Cr(6) and four equivalent Cr(4) atoms to form NCr6 octahedra that share corners with two equivalent C(1)Cr6 octahedra and edges with two equivalent N(1)Cr6 octahedra. The corner-sharing octahedral tilt angles are 25°.