DOE OSTI2020
Ba(Co5As3)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 12-coordinate geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.24–3.66 Å. There are seven inequivalent Co+1.60+ sites. In the first Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of distorted edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.40–2.44 Å. In the second Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.28–2.42 Å. In the third Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.32–2.43 Å. In the fourth Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.25–2.35 Å. In the fifth Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.30–2.39 Å. In the sixth Co+1.60+ site, Co+1.60+ is bonded in a 3-coordinate geometry to three As3- atoms. There are one shorter (2.43 Å) and two longer (2.46 Å) Co–As bond lengths. In the seventh Co+1.60+ site, Co+1.60+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.31–2.46 Å. There are five inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Ba2+ and six Co+1.60+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to one Ba2+ and eight Co+1.60+ atoms. In the third As3- site, As3- is bonded in a 9-coordinate geometry to one Ba2+ and seven Co+1.60+ atoms. In the fourth As3- site, As3- is bonded in a 6-coordinate geometry to one Ba2+ and six Co+1.60+ atoms. In the fifth As3- site, As3- is bonded in a 6-coordinate geometry to one Ba2+ and six Co+1.60+ atoms.