Materials Data on KBaAsSe3 by Materials Project
KBaAsSe3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.33–3.89 Å. Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.32–3.66 Å. As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.41 Å) and one longer (2.48 Å) As–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent K1+, two equivalent Ba2+, and one As3+ atom. In the second Se2- site, Se2- is bonded to one K1+, four equivalent Ba2+, and one As3+ atom to form a mixture of distorted corner and edge-sharing SeKBa4As octahedra. The corner-sharing octahedra tilt angles range from 25–36°. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent K1+, two equivalent Ba2+, and one As3+ atom.