CaFe4As3 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 7-coordinate geometry to two equivalent As(1), two equivalent As(2), and three equivalent As(3) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(1), one As(2), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to one As(1), one As(3), and two equivalent As(2) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. In the fourth Fe site, Fe(4) is bonded to one As(2) and three equivalent As(1) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), one Fe(1), one Fe(2), two equivalent Fe(3), and three equivalent Fe(4) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Ca(1), one Fe(1), one Fe(4), two equivalent Fe(2), and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 7-coordinate geometry to three equivalent Ca(1), one Fe(2), one Fe(3), and two equivalent Fe(1) atoms.
CaFe4As3 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 7-coordinate geometry to two equivalent As(1), two equivalent As(2), and three equivalent As(3) atoms. Both Ca(1)-As(1) bond lengths are 3.09 Å. Both Ca(1)-As(2) bond lengths are 2.96 Å. There are two shorter (2.98 Å) and one longer (3.28 Å) Ca(1)-As(3) bond length. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(1), one As(2), and two equivalent As(3) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. The Fe(1)-As(1) bond length is 2.39 Å. The Fe(1)-As(2) bond length is 2.38 Å. Both Fe(1)-As(3) bond lengths are 2.41 Å. In the second Fe site, Fe(2) is bonded to one As(1), one As(3), and two equivalent As(2) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. The Fe(2)-As(1) bond length is 2.45 Å. The Fe(2)-As(3) bond length is 2.43 Å. Both Fe(2)-As(2) bond lengths are 2.46 Å. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. The Fe(3)-As(3) bond length is 2.40 Å. Both Fe(3)-As(1) bond lengths are 2.61 Å. Both Fe(3)-As(2) bond lengths are 2.48 Å. In the fourth Fe site, Fe(4) is bonded to one As(2) and three equivalent As(1) atoms to form a mixture of distorted corner and edge-sharing FeAs4 tetrahedra. The Fe(4)-As(2) bond length is 2.34 Å. There is one shorter (2.35 Å) and two longer (2.38 Å) Fe(4)-As(1) bond lengths. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), one Fe(1), one Fe(2), two equivalent Fe(3), and three equivalent Fe(4) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Ca(1), one Fe(1), one Fe(4), two equivalent Fe(2), and two equivalent Fe(3) atoms. In the third As site, As(3) is bonded in a 7-coordinate geometry to three equivalent Ca(1), one Fe(2), one Fe(3), and two equivalent Fe(1) atoms.