Materials Data on SrCa3 by Materials Project

Abstract

SrCa3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr is bonded to twelve Ca atoms to form SrCa12 cuboctahedra that share corners with four equivalent SrCa12 cuboctahedra, corners with eight equivalent CaSr4Ca8 cuboctahedra, edges with eight equivalent SrCa12 cuboctahedra, edges with sixteen equivalent CaSr4Ca8 cuboctahedra, faces with four equivalent SrCa12 cuboctahedra, and faces with fourteen CaSr4Ca8 cuboctahedra. There are eight shorter (3.98 Å) and four longer (4.01 Å) Sr–Ca bond lengths. There are two inequivalent Ca sites. In the first Ca site, Ca is bonded to four equivalent Sr and eight Ca atoms to form CaSr4Ca8 cuboctahedra that share corners with twelve equivalent CaSr4Ca8 cuboctahedra, edges with eight equivalent SrCa12 cuboctahedra, edges with sixteen CaSr4Ca8 cuboctahedra, faces with four equivalent SrCa12 cuboctahedra, and faces with fourteen CaSr4Ca8 cuboctahedra. There are four shorter (3.98 Å) and four longer (4.01 Å) Ca–Ca bond lengths. In the second Ca site, Ca is bonded to four equivalent Sr and eight equivalent Ca atoms to form CaSr4Ca8 cuboctahedra that share corners with four equivalent CaSr4Ca8 cuboctahedra, corners with eight equivalent SrCa12 cuboctahedra, edges with twenty-four CaSr4Ca8 cuboctahedra, faces with six equivalent SrCa12 cuboctahedra, and faces with twelve CaSr4Ca8 cuboctahedra.