Materials Data on CaPr3 by Materials Project
CaPr3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ca is bonded to twelve Pr atoms to form CaPr12 cuboctahedra that share corners with six equivalent CaPr12 cuboctahedra, corners with twelve PrCa4Pr8 cuboctahedra, edges with eighteen PrCa4Pr8 cuboctahedra, faces with eight equivalent CaPr12 cuboctahedra, and faces with twelve PrCa4Pr8 cuboctahedra. There are six shorter (3.75 Å) and six longer (3.77 Å) Ca–Pr bond lengths. There are two inequivalent Pr sites. In the first Pr site, Pr is bonded to four equivalent Ca and eight Pr atoms to form PrCa4Pr8 cuboctahedra that share corners with four equivalent CaPr12 cuboctahedra, corners with fourteen PrCa4Pr8 cuboctahedra, edges with six equivalent CaPr12 cuboctahedra, edges with twelve PrCa4Pr8 cuboctahedra, faces with four equivalent CaPr12 cuboctahedra, and faces with sixteen PrCa4Pr8 cuboctahedra. There are a spread of Pr–Pr bond distances ranging from 3.72–3.81 Å. In the second Pr site, Pr is bonded to four equivalent Ca and eight Pr atoms to form PrCa4Pr8 cuboctahedra that share corners with four equivalent CaPr12 cuboctahedra, corners with fourteen PrCa4Pr8 cuboctahedra, edges with six equivalent CaPr12 cuboctahedra, edges with twelve PrCa4Pr8 cuboctahedra, faces with four equivalent CaPr12 cuboctahedra, and faces with sixteen PrCa4Pr8 cuboctahedra. Both Pr–Pr bond lengths are 3.72 Å.