BaSr4 is alpha La-derived structured and crystallizes in the trigonal R-3m space group. Ba(1) is bonded to six equivalent Ba(1) and six equivalent Sr(1) atoms to form BaBa6Sr6 cuboctahedra that share corners with six equivalent Ba(1)Ba6Sr6 cuboctahedra, corners with six equivalent Sr(2)Sr12 cuboctahedra, edges with six equivalent Ba(1)Ba6Sr6 cuboctahedra, edges with six equivalent Sr(2)Sr12 cuboctahedra, edges with twelve equivalent Sr(1)Ba3Sr9 cuboctahedra, faces with six equivalent Ba(1)Ba6Sr6 cuboctahedra, and faces with twelve equivalent Sr(1)Ba3Sr9 cuboctahedra. There are six inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to three equivalent Ba(1), three equivalent Sr(2), and six equivalent Sr(1) atoms to form SrBa3Sr9 cuboctahedra that share corners with three equivalent Sr(2)Sr12 cuboctahedra; corners with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with six equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with nine Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Ba(1)Ba6Sr6 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with six equivalent Sr(2)Sr12 cuboctahedra. In the second Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. In the third Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. In the fourth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. In the fifth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. In the sixth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra.
BaSr4 is alpha La-derived structured and crystallizes in the trigonal R-3m space group. Ba(1) is bonded to six equivalent Ba(1) and six equivalent Sr(1) atoms to form BaBa6Sr6 cuboctahedra that share corners with six equivalent Ba(1)Ba6Sr6 cuboctahedra, corners with six equivalent Sr(2)Sr12 cuboctahedra, edges with six equivalent Ba(1)Ba6Sr6 cuboctahedra, edges with six equivalent Sr(2)Sr12 cuboctahedra, edges with twelve equivalent Sr(1)Ba3Sr9 cuboctahedra, faces with six equivalent Ba(1)Ba6Sr6 cuboctahedra, and faces with twelve equivalent Sr(1)Ba3Sr9 cuboctahedra. All Ba(1)-Ba(1) bond lengths are 4.30 Å. All Ba(1)-Sr(1) bond lengths are 4.35 Å. There are six inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to three equivalent Ba(1), three equivalent Sr(2), and six equivalent Sr(1) atoms to form SrBa3Sr9 cuboctahedra that share corners with three equivalent Sr(2)Sr12 cuboctahedra; corners with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with six equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with nine Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Ba(1)Ba6Sr6 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with six equivalent Sr(2)Sr12 cuboctahedra. All Sr(1)-Sr(2) bond lengths are 4.28 Å. All Sr(1)-Sr(1) bond lengths are 4.30 Å. In the second Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. All Sr(2)-Sr(2,2) bond lengths are 4.30 Å. In the third Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. All Sr(2)-Sr(1) bond lengths are 4.28 Å. All Sr(2)-Sr(2) bond lengths are 4.30 Å. In the fourth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. All Sr(2)-Sr(1) bond lengths are 4.28 Å. All Sr(2)-Sr(2,2) bond lengths are 4.30 Å. In the fifth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. All Sr(2)-Sr(1) bond lengths are 4.28 Å. All Sr(2)-Sr(2) bond lengths are 4.30 Å. In the sixth Sr site, Sr(2) is bonded to three equivalent Sr(1) and nine Sr(2,2) atoms to form SrSr12 cuboctahedra that share corners with three equivalent Ba(1)Ba6Sr6 cuboctahedra; corners with three equivalent Sr(1)Ba3Sr9 cuboctahedra; corners with six equivalent Sr(2)Sr12 cuboctahedra; edges with three equivalent Ba(1)Ba6Sr6 cuboctahedra; edges with nine equivalent Sr(1)Ba3Sr9 cuboctahedra; edges with twelve Sr(2,2)Sr12 cuboctahedra; faces with six equivalent Sr(1)Ba3Sr9 cuboctahedra; and faces with twelve Sr(2,2)Sr12 cuboctahedra. All Sr(2)-Sr(1) bond lengths are 4.28 Å. All Sr(2)-Sr(2,2) bond lengths are 4.30 Å.