DOE OSTI2020
Ag3AsSe3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are five inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.62–3.26 Å. In the second Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to four Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.68–3.17 Å. In the third Ag1+ site, Ag1+ is bonded to four Se2- atoms to form a mixture of distorted edge and corner-sharing AgSe4 tetrahedra. There are a spread of Ag–Se bond distances ranging from 2.69–2.85 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are two shorter (2.72 Å) and two longer (2.99 Å) Ag–Se bond lengths. In the fifth Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.64–2.76 Å. There are three inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.43 Å) and two longer (2.45 Å) As–Se bond lengths. In the second As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.45 Å) and one longer (2.47 Å) As–Se bond lengths. In the third As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.44 Å) and one longer (2.47 Å) As–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ag1+ and one As3+ atom. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three Ag1+ and one As3+ atom. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to five Ag1+ and one As3+ atom. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ag1+ and one As3+ atom. In the fifth Se2- site, Se2- is bonded in a 7-coordinate geometry to six Ag1+ and one As3+ atom. In the sixth Se2- site, Se2- is bonded to three Ag1+ and one As3+ atom to form distorted corner-sharing SeAg3As trigonal pyramids.