Materials Data on SrPa3 by Materials Project
SrPa3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr is bonded to twelve Pa atoms to form SrPa12 cuboctahedra that share corners with four equivalent SrPa12 cuboctahedra, corners with eight equivalent PaSr4Pa8 cuboctahedra, edges with eight equivalent SrPa12 cuboctahedra, edges with sixteen equivalent PaSr4Pa8 cuboctahedra, faces with four equivalent SrPa12 cuboctahedra, and faces with fourteen PaSr4Pa8 cuboctahedra. There are eight shorter (3.37 Å) and four longer (3.39 Å) Sr–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Sr and eight Pa atoms to form distorted PaSr4Pa8 cuboctahedra that share corners with twelve equivalent PaSr4Pa8 cuboctahedra, edges with eight equivalent SrPa12 cuboctahedra, edges with sixteen PaSr4Pa8 cuboctahedra, faces with four equivalent SrPa12 cuboctahedra, and faces with fourteen PaSr4Pa8 cuboctahedra. There are four shorter (3.37 Å) and four longer (3.39 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Sr and eight equivalent Pa atoms to form distorted PaSr4Pa8 cuboctahedra that share corners with four equivalent PaSr4Pa8 cuboctahedra, corners with eight equivalent SrPa12 cuboctahedra, edges with twenty-four PaSr4Pa8 cuboctahedra, faces with six equivalent SrPa12 cuboctahedra, and faces with twelve PaSr4Pa8 cuboctahedra.