Co2As crystallizes in the hexagonal P-6m2 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to two equivalent Co(1), six equivalent Co(2), and six equivalent As(1) atoms. In the second Co site, Co(2) is bonded in a trigonal planar geometry to six equivalent Co(1) and three equivalent As(1) atoms. As(1) is bonded in a 3-coordinate geometry to three equivalent Co(2) and six equivalent Co(1) atoms.
Co2As crystallizes in the hexagonal P-6m2 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to two equivalent Co(1), six equivalent Co(2), and six equivalent As(1) atoms. Both Co(1)-Co(1) bond lengths are 2.76 Å. All Co(1)-Co(2) bond lengths are 2.65 Å. All Co(1)-As(1) bond lengths are 2.65 Å. In the second Co site, Co(2) is bonded in a trigonal planar geometry to six equivalent Co(1) and three equivalent As(1) atoms. All Co(2)-As(1) bond lengths are 2.26 Å. As(1) is bonded in a 3-coordinate geometry to three equivalent Co(2) and six equivalent Co(1) atoms.