Cr(FeAs3)2 crystallizes in the monoclinic P2/m space group. Cr(1) is bonded to one As(1), one As(2), two equivalent As(4), and two equivalent As(5) atoms to form CrAs6 octahedra that share corners with four equivalent Fe(2)As6 octahedra, corners with four equivalent Fe(3)As6 octahedra, and edges with two equivalent Cr(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent As(3) and four equivalent As(6) atoms to form a mixture of corner and edge-sharing FeAs6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Fe site, Fe(2) is bonded to one As(4), one As(6), two equivalent As(1), and two equivalent As(3) atoms to form FeAs6 octahedra that share corners with four equivalent Cr(1)As6 octahedra, corners with four equivalent Fe(1)As6 octahedra, and edges with two equivalent Fe(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the third Fe site, Fe(3) is bonded to two equivalent As(5) and four equivalent As(2) atoms to form FeAs6 octahedra that share corners with eight equivalent Cr(1)As6 octahedra and edges with two equivalent Fe(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth As site, As(4) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(2) atom. In the fifth As site, As(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(3) atom. In the sixth As site, As(6) is bonded in a 3-coordinate geometry to one Fe(2) and two equivalent Fe(1) atoms.
Cr(FeAs3)2 crystallizes in the monoclinic P2/m space group. Cr(1) is bonded to one As(1), one As(2), two equivalent As(4), and two equivalent As(5) atoms to form CrAs6 octahedra that share corners with four equivalent Fe(2)As6 octahedra, corners with four equivalent Fe(3)As6 octahedra, and edges with two equivalent Cr(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. The Cr(1)-As(1) bond length is 2.49 Å. The Cr(1)-As(2) bond length is 2.47 Å. Both Cr(1)-As(4) bond lengths are 2.47 Å. Both Cr(1)-As(5) bond lengths are 2.47 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent As(3) and four equivalent As(6) atoms to form a mixture of corner and edge-sharing FeAs6 octahedra. The corner-sharing octahedral tilt angles are 53°. Both Fe(1)-As(3) bond lengths are 2.39 Å. All Fe(1)-As(6) bond lengths are 2.40 Å. In the second Fe site, Fe(2) is bonded to one As(4), one As(6), two equivalent As(1), and two equivalent As(3) atoms to form FeAs6 octahedra that share corners with four equivalent Cr(1)As6 octahedra, corners with four equivalent Fe(1)As6 octahedra, and edges with two equivalent Fe(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-53°. The Fe(2)-As(4) bond length is 2.38 Å. The Fe(2)-As(6) bond length is 2.37 Å. Both Fe(2)-As(1) bond lengths are 2.38 Å. Both Fe(2)-As(3) bond lengths are 2.41 Å. In the third Fe site, Fe(3) is bonded to two equivalent As(5) and four equivalent As(2) atoms to form FeAs6 octahedra that share corners with eight equivalent Cr(1)As6 octahedra and edges with two equivalent Fe(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. Both Fe(3)-As(5) bond lengths are 2.35 Å. All Fe(3)-As(2) bond lengths are 2.37 Å. There are six inequivalent As sites. In the first As site, As(1) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(2) atoms. In the second As site, As(2) is bonded in a 3-coordinate geometry to one Cr(1) and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth As site, As(4) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(2) atom. In the fifth As site, As(5) is bonded in a 3-coordinate geometry to two equivalent Cr(1) and one Fe(3) atom. In the sixth As site, As(6) is bonded in a 3-coordinate geometry to one Fe(2) and two equivalent Fe(1) atoms.