Materials Data on Ca2As3 by Materials Project
Ca2As3 is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are five inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight As+1.33- atoms. There are a spread of Ca–As bond distances ranging from 3.05–3.34 Å. In the second Ca2+ site, Ca2+ is bonded to eight As+1.33- atoms to form a mixture of distorted face, edge, and corner-sharing CaAs8 hexagonal bipyramids. There are a spread of Ca–As bond distances ranging from 3.00–3.37 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to nine As+1.33- atoms. There are a spread of Ca–As bond distances ranging from 3.03–3.55 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight As+1.33- atoms. There are a spread of Ca–As bond distances ranging from 3.07–3.23 Å. In the fifth Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to ten As+1.33- atoms. There are a spread of Ca–As bond distances ranging from 2.95–3.47 Å. There are six inequivalent As+1.33- sites. In the first As+1.33- site, As+1.33- is bonded in a 7-coordinate geometry to six Ca2+ and one As+1.33- atom. The As–As bond length is 2.54 Å. In the second As+1.33- site, As+1.33- is bonded in a 7-coordinate geometry to five Ca2+ and two As+1.33- atoms. There are one shorter (2.54 Å) and one longer (2.64 Å) As–As bond lengths. In the third As+1.33- site, As+1.33- is bonded in a 8-coordinate geometry to six Ca2+ and two As+1.33- atoms. There are one shorter (2.53 Å) and one longer (2.56 Å) As–As bond lengths. In the fourth As+1.33- site, As+1.33- is bonded in a 7-coordinate geometry to six Ca2+ and one As+1.33- atom. In the fifth As+1.33- site, As+1.33- is bonded in a 7-coordinate geometry to five Ca2+ and two As+1.33- atoms. The As–As bond length is 2.51 Å. In the sixth As+1.33- site, As+1.33- is bonded in a 7-coordinate geometry to six Ca2+ and two As+1.33- atoms.