Materials Data on SrCa3 by Materials Project

Abstract

SrCa3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Sr is bonded to twelve Ca atoms to form SrCa12 cuboctahedra that share corners with six equivalent SrCa12 cuboctahedra, corners with twelve CaSr4Ca8 cuboctahedra, edges with eighteen CaSr4Ca8 cuboctahedra, faces with eight equivalent SrCa12 cuboctahedra, and faces with twelve CaSr4Ca8 cuboctahedra. There are six shorter (3.99 Å) and six longer (4.03 Å) Sr–Ca bond lengths. There are three 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 four equivalent SrCa12 cuboctahedra, corners with fourteen CaSr4Ca8 cuboctahedra, edges with six equivalent SrCa12 cuboctahedra, edges with twelve CaSr4Ca8 cuboctahedra, faces with four equivalent SrCa12 cuboctahedra, and faces with sixteen CaSr4Ca8 cuboctahedra. There are a spread of Ca–Ca bond distances ranging from 3.93–4.04 Å. In the second Ca site, Ca is bonded to four equivalent Sr and eight Ca atoms to form CaSr4Ca8 cuboctahedra that share corners with four equivalent SrCa12 cuboctahedra, corners with fourteen CaSr4Ca8 cuboctahedra, edges with six equivalent SrCa12 cuboctahedra, edges with twelve CaSr4Ca8 cuboctahedra, faces with four equivalent SrCa12 cuboctahedra, and faces with sixteen CaSr4Ca8 cuboctahedra. Both Ca–Ca bond lengths are 4.00 Å. In the third Ca site, Ca is bonded to four equivalent Sr and eight Ca atoms to form CaSr4Ca8 cuboctahedra that share corners with four equivalent SrCa12 cuboctahedra, corners with fourteen CaSr4Ca8 cuboctahedra, edges with six equivalent SrCa12 cuboctahedra, edges with twelve CaSr4Ca8 cuboctahedra, faces with four equivalent SrCa12 cuboctahedra, and faces with sixteen CaSr4Ca8 cuboctahedra.