Materials Data on SrAc3 by Materials Project

Abstract

SrAc3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr is bonded to twelve Ac atoms to form SrAc12 cuboctahedra that share corners with four equivalent SrAc12 cuboctahedra, corners with eight equivalent AcSr4Ac8 cuboctahedra, edges with eight equivalent SrAc12 cuboctahedra, edges with sixteen equivalent AcSr4Ac8 cuboctahedra, faces with four equivalent SrAc12 cuboctahedra, and faces with fourteen AcSr4Ac8 cuboctahedra. There are eight shorter (4.04 Å) and four longer (4.06 Å) Sr–Ac bond lengths. There are two inequivalent Ac sites. In the first Ac site, Ac is bonded to four equivalent Sr and eight equivalent Ac atoms to form AcSr4Ac8 cuboctahedra that share corners with four equivalent AcSr4Ac8 cuboctahedra, corners with eight equivalent SrAc12 cuboctahedra, edges with twenty-four AcSr4Ac8 cuboctahedra, faces with six equivalent SrAc12 cuboctahedra, and faces with twelve AcSr4Ac8 cuboctahedra. All Ac–Ac bond lengths are 4.04 Å. In the second Ac site, Ac is bonded to four equivalent Sr and eight Ac atoms to form AcSr4Ac8 cuboctahedra that share corners with twelve equivalent AcSr4Ac8 cuboctahedra, edges with eight equivalent SrAc12 cuboctahedra, edges with sixteen AcSr4Ac8 cuboctahedra, faces with four equivalent SrAc12 cuboctahedra, and faces with fourteen AcSr4Ac8 cuboctahedra. All Ac–Ac bond lengths are 4.06 Å.