BaSr3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to four equivalent Sr(2) and eight equivalent Sr(1) atoms to form BaSr12 cuboctahedra that share corners with four equivalent Ba(1)Sr12 cuboctahedra, corners with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, edges with eight equivalent Ba(1)Sr12 cuboctahedra, edges with sixteen equivalent Sr(1)Ba4Sr8 cuboctahedra, faces with four equivalent Ba(1)Sr12 cuboctahedra, faces with six equivalent Sr(2)Ba4Sr8 cuboctahedra, and faces with eight equivalent Sr(1)Ba4Sr8 cuboctahedra. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent Ba(1), four equivalent Sr(1), and four equivalent Sr(2) atoms to form SrBa4Sr8 cuboctahedra that share corners with twelve equivalent Sr(1)Ba4Sr8 cuboctahedra, edges with eight equivalent Ba(1)Sr12 cuboctahedra, edges with eight equivalent Sr(1)Ba4Sr8 cuboctahedra, edges with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, faces with four equivalent Ba(1)Sr12 cuboctahedra, faces with four equivalent Sr(2)Ba4Sr8 cuboctahedra, and faces with ten equivalent Sr(1)Ba4Sr8 cuboctahedra. In the second Sr site, Sr(2) is bonded to four equivalent Ba(1) and eight equivalent Sr(1) atoms to form SrBa4Sr8 cuboctahedra that share corners with four equivalent Sr(2)Ba4Sr8 cuboctahedra, corners with eight equivalent Ba(1)Sr12 cuboctahedra, edges with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, edges with sixteen equivalent Sr(1)Ba4Sr8 cuboctahedra, faces with four equivalent Sr(2)Ba4Sr8 cuboctahedra, faces with six equivalent Ba(1)Sr12 cuboctahedra, and faces with eight equivalent Sr(1)Ba4Sr8 cuboctahedra.
BaSr3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to four equivalent Sr(2) and eight equivalent Sr(1) atoms to form BaSr12 cuboctahedra that share corners with four equivalent Ba(1)Sr12 cuboctahedra, corners with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, edges with eight equivalent Ba(1)Sr12 cuboctahedra, edges with sixteen equivalent Sr(1)Ba4Sr8 cuboctahedra, faces with four equivalent Ba(1)Sr12 cuboctahedra, faces with six equivalent Sr(2)Ba4Sr8 cuboctahedra, and faces with eight equivalent Sr(1)Ba4Sr8 cuboctahedra. All Ba(1)-Sr(2) bond lengths are 4.39 Å. All Ba(1)-Sr(1) bond lengths are 4.37 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent Ba(1), four equivalent Sr(1), and four equivalent Sr(2) atoms to form SrBa4Sr8 cuboctahedra that share corners with twelve equivalent Sr(1)Ba4Sr8 cuboctahedra, edges with eight equivalent Ba(1)Sr12 cuboctahedra, edges with eight equivalent Sr(1)Ba4Sr8 cuboctahedra, edges with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, faces with four equivalent Ba(1)Sr12 cuboctahedra, faces with four equivalent Sr(2)Ba4Sr8 cuboctahedra, and faces with ten equivalent Sr(1)Ba4Sr8 cuboctahedra. All Sr(1)-Sr(1) bond lengths are 4.39 Å. All Sr(1)-Sr(2) bond lengths are 4.37 Å. In the second Sr site, Sr(2) is bonded to four equivalent Ba(1) and eight equivalent Sr(1) atoms to form SrBa4Sr8 cuboctahedra that share corners with four equivalent Sr(2)Ba4Sr8 cuboctahedra, corners with eight equivalent Ba(1)Sr12 cuboctahedra, edges with eight equivalent Sr(2)Ba4Sr8 cuboctahedra, edges with sixteen equivalent Sr(1)Ba4Sr8 cuboctahedra, faces with four equivalent Sr(2)Ba4Sr8 cuboctahedra, faces with six equivalent Ba(1)Sr12 cuboctahedra, and faces with eight equivalent Sr(1)Ba4Sr8 cuboctahedra.