Materials Data on Sm2CuAs3O by Materials Project
Sm2CuAs3O crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Sm+2.50+ sites. In the first Sm+2.50+ site, Sm+2.50+ is bonded in a 4-coordinate geometry to four As+1.33- and four equivalent O2- atoms. There are two shorter (3.23 Å) and two longer (3.27 Å) Sm–As bond lengths. There are two shorter (2.30 Å) and two longer (2.31 Å) Sm–O bond lengths. In the second Sm+2.50+ site, Sm+2.50+ is bonded in a 8-coordinate geometry to eight As+1.33- atoms. There are a spread of Sm–As bond distances ranging from 3.01–3.18 Å. Cu1+ is bonded to four equivalent As+1.33- atoms to form a mixture of edge and corner-sharing CuAs4 tetrahedra. All Cu–As bond lengths are 2.53 Å. There are three inequivalent As+1.33- sites. In the first As+1.33- site, As+1.33- is bonded in a 6-coordinate geometry to four Sm+2.50+ and four equivalent As+1.33- atoms. There are two shorter (2.61 Å) and two longer (3.06 Å) As–As bond lengths. In the second As+1.33- site, As+1.33- is bonded in a 8-coordinate geometry to four Sm+2.50+ and four equivalent As+1.33- atoms. In the third As+1.33- site, As+1.33- is bonded in a 8-coordinate geometry to four equivalent Sm+2.50+ and four equivalent Cu1+ atoms. O2- is bonded to four equivalent Sm+2.50+ atoms to form a mixture of edge and corner-sharing OSm4 tetrahedra.