Materials Data on Pr2CrSe4 by Materials Project
Pr2CrSe4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Pr3+ is bonded to six Se2- atoms to form PrSe6 octahedra that share corners with six equivalent CrSe6 octahedra, edges with six equivalent PrSe6 octahedra, and a faceface with one CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 41–58°. There are a spread of Pr–Se bond distances ranging from 2.93–3.03 Å. Cr2+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with twelve equivalent PrSe6 octahedra, edges with two equivalent CrSe6 octahedra, and faces with two equivalent PrSe6 octahedra. The corner-sharing octahedra tilt angles range from 41–58°. There are two shorter (2.57 Å) and four longer (2.78 Å) Cr–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three equivalent Pr3+ and one Cr2+ atom. In the second Se2- site, Se2- is bonded to three equivalent Pr3+ and two equivalent Cr2+ atoms to form a mixture of distorted edge and corner-sharing SePr3Cr2 square pyramids.