Materials Data on K2Zn3SiAs4 by Materials Project
K2Zn3SiAs4 is alpha bismuth trifluoride-derived structured and crystallizes in the orthorhombic C222 space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. There are a spread of K–As bond distances ranging from 3.48–3.66 Å. There are three inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four equivalent As3- atoms to form ZnAs4 tetrahedra that share corners with four equivalent SiAs4 tetrahedra and edges with four ZnAs4 tetrahedra. All Zn–As bond lengths are 2.67 Å. In the second Zn2+ site, Zn2+ is bonded to four equivalent As3- atoms to form ZnAs4 tetrahedra that share corners with four equivalent ZnAs4 tetrahedra, edges with two equivalent ZnAs4 tetrahedra, and edges with two equivalent SiAs4 tetrahedra. All Zn–As bond lengths are 2.56 Å. In the third Zn2+ site, Zn2+ is bonded to four equivalent As3- atoms to form ZnAs4 tetrahedra that share corners with four equivalent ZnAs4 tetrahedra, edges with two equivalent ZnAs4 tetrahedra, and edges with two equivalent SiAs4 tetrahedra. All Zn–As bond lengths are 2.56 Å. Si4+ is bonded to four equivalent As3- atoms to form SiAs4 tetrahedra that share corners with four equivalent ZnAs4 tetrahedra and edges with four ZnAs4 tetrahedra. All Si–As bond lengths are 2.44 Å. As3- is bonded in a 8-coordinate geometry to four equivalent K1+, three Zn2+, and one Si4+ atom.