Materials Data on Pr3(SiC)2 by Materials Project

Abstract

Pr3Si2C2 crystallizes in the orthorhombic Cmm2 space group. The structure is three-dimensional. there are two inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a 8-coordinate geometry to six equivalent Si4- and two equivalent C+0.50- atoms. There are four shorter (3.11 Å) and two longer (3.15 Å) Pr–Si bond lengths. Both Pr–C bond lengths are 2.72 Å. In the second Pr3+ site, Pr3+ is bonded to two equivalent Si4- and four equivalent C+0.50- atoms to form distorted PrSi2C4 octahedra that share corners with four equivalent CPr4C trigonal bipyramids and edges with two equivalent PrSi2C4 octahedra. Both Pr–Si bond lengths are 3.40 Å. All Pr–C bond lengths are 2.60 Å. Si4- is bonded in a 9-coordinate geometry to seven Pr3+ and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.66 Å. C+0.50- is bonded to four Pr3+ and one C+0.50- atom to form distorted CPr4C trigonal bipyramids that share corners with two equivalent PrSi2C4 octahedra, corners with four equivalent CPr4C trigonal bipyramids, and edges with two equivalent CPr4C trigonal bipyramids. The corner-sharing octahedral tilt angles are 54°. The C–C bond length is 1.28 Å.