Materials Data on KPrGeSe4 by Materials Project

Abstract

KPrGeSe4 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.45–4.00 Å. Pr3+ is bonded to seven Se2- atoms to form distorted PrSe7 pentagonal bipyramids that share corners with two equivalent PrSe7 pentagonal bipyramids, a cornercorner with one GeSe4 tetrahedra, edges with two equivalent PrSe7 pentagonal bipyramids, and edges with three equivalent GeSe4 tetrahedra. There are a spread of Pr–Se bond distances ranging from 3.03–3.17 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share a cornercorner with one PrSe7 pentagonal bipyramid and edges with three equivalent PrSe7 pentagonal bipyramids. There are a spread of Ge–Se bond distances ranging from 2.35–2.39 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent K1+, two equivalent Pr3+, and one Ge4+ atom. In the second Se2- site, Se2- is bonded to two equivalent K1+, two equivalent Pr3+, and one Ge4+ atom to form distorted corner-sharing SeK2Pr2Ge square pyramids. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent K1+, one Pr3+, and one Ge4+ atom. In the fourth Se2- site, Se2- is bonded in a distorted see-saw-like geometry to one K1+, two equivalent Pr3+, and one Ge4+ atom.