Co5As2 crystallizes in the hexagonal P6_3cm space group. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded in a 4-coordinate geometry to one As(1) and three equivalent As(3) atoms. In the second Co site, Co(2) is bonded in a 4-coordinate geometry to one As(2) and three equivalent As(3) atoms. In the third Co site, Co(3) is bonded in a 3-coordinate geometry to one As(1) and two equivalent As(3) atoms. In the fourth Co site, Co(4) is bonded in a 4-coordinate geometry to one As(1), one As(3), and two equivalent As(2) atoms. In the fifth Co site, Co(5) is bonded in a 4-coordinate geometry to one As(1), one As(3), and two equivalent As(2) atoms. In the sixth Co site, Co(6) is bonded in a 1-coordinate geometry to two equivalent As(2) and three equivalent As(3) atoms. There are three inequivalent As sites. In the first As site, As(2) is bonded in a 10-coordinate geometry to one Co(2), three equivalent Co(4), three equivalent Co(5), and three equivalent Co(6) atoms. In the second As site, As(3) is bonded in a 10-coordinate geometry to one Co(1), one Co(4), one Co(5), two equivalent Co(2), two equivalent Co(3), and three equivalent Co(6) atoms. In the third As site, As(1) is bonded in a 10-coordinate geometry to one Co(1), three equivalent Co(3), three equivalent Co(4), and three equivalent Co(5) atoms.
Co5As2 crystallizes in the hexagonal P6_3cm space group. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded in a 4-coordinate geometry to one As(1) and three equivalent As(3) atoms. The Co(1)-As(1) bond length is 2.50 Å. All Co(1)-As(3) bond lengths are 2.39 Å. In the second Co site, Co(2) is bonded in a 4-coordinate geometry to one As(2) and three equivalent As(3) atoms. The Co(2)-As(2) bond length is 2.53 Å. All Co(2)-As(3) bond lengths are 2.44 Å. In the third Co site, Co(3) is bonded in a 3-coordinate geometry to one As(1) and two equivalent As(3) atoms. The Co(3)-As(1) bond length is 2.42 Å. Both Co(3)-As(3) bond lengths are 2.41 Å. In the fourth Co site, Co(4) is bonded in a 4-coordinate geometry to one As(1), one As(3), and two equivalent As(2) atoms. The Co(4)-As(1) bond length is 2.57 Å. The Co(4)-As(3) bond length is 2.45 Å. Both Co(4)-As(2) bond lengths are 2.35 Å. In the fifth Co site, Co(5) is bonded in a 4-coordinate geometry to one As(1), one As(3), and two equivalent As(2) atoms. The Co(5)-As(1) bond length is 2.29 Å. The Co(5)-As(3) bond length is 2.40 Å. Both Co(5)-As(2) bond lengths are 2.39 Å. In the sixth Co site, Co(6) is bonded in a 1-coordinate geometry to two equivalent As(2) and three equivalent As(3) atoms. Both Co(6)-As(2) bond lengths are 2.71 Å. There is one shorter (2.35 Å) and two longer (2.65 Å) Co(6)-As(3) bond lengths. There are three inequivalent As sites. In the first As site, As(2) is bonded in a 10-coordinate geometry to one Co(2), three equivalent Co(4), three equivalent Co(5), and three equivalent Co(6) atoms. In the second As site, As(3) is bonded in a 10-coordinate geometry to one Co(1), one Co(4), one Co(5), two equivalent Co(2), two equivalent Co(3), and three equivalent Co(6) atoms. In the third As site, As(1) is bonded in a 10-coordinate geometry to one Co(1), three equivalent Co(3), three equivalent Co(4), and three equivalent Co(5) atoms.