Ba2(CaAl3)3 is Bergman Structure: Mg32(Al,Zn)49 Bergman-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to three equivalent Ca(3), three equivalent Al(1), three equivalent Al(2), and three equivalent Al(3) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Ca(2), one Al(2), three equivalent Al(1), and six equivalent Al(4) atoms. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ca(3), three equivalent Ca(2), three equivalent Al(4), three equivalent Al(5), and six equivalent Al(3) atoms. In the second Ca site, Ca(2) is bonded in a 16-coordinate geometry to one Ba(2), three equivalent Ca(1), three equivalent Al(3), three equivalent Al(5), and six equivalent Al(4) atoms. In the third Ca site, Ca(3) is bonded in a 14-coordinate geometry to three equivalent Ba(1), one Ca(1), one Al(1), three equivalent Al(2), and six equivalent Al(3) atoms. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to three equivalent Ba(1), three equivalent Ba(2), one Ca(3), and three equivalent Al(4) atoms. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one Ba(2), three equivalent Ba(1), three equivalent Ca(3), and three equivalent Al(3) atoms. In the third Al site, Al(3) is bonded to one Ba(1), one Ca(2), two equivalent Ca(1), two equivalent Ca(3), one Al(2), one Al(5), and four equivalent Al(3) atoms to form distorted AlBaCa5Al6 cuboctahedra that share corners with two equivalent Al(5)Ca6Al6 cuboctahedra, corners with four equivalent Al(3)BaCa5Al6 cuboctahedra, edges with two equivalent Al(3)BaCa5Al6 cuboctahedra, faces with three equivalent Al(5)Ca6Al6 cuboctahedra, and faces with eight equivalent Al(3)BaCa5Al6 cuboctahedra. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to two equivalent Ba(2), one Ca(1), two equivalent Ca(2), one Al(1), one Al(5), and four equivalent Al(4) atoms. In the fifth Al site, Al(5) is bonded to three equivalent Ca(1), three equivalent Ca(2), three equivalent Al(3), and three equivalent Al(4) atoms to form AlCa6Al6 cuboctahedra that share corners with six equivalent Al(3)BaCa5Al6 cuboctahedra, edges with six equivalent Al(5)Ca6Al6 cuboctahedra, and faces with nine equivalent Al(3)BaCa5Al6 cuboctahedra.
Ba2(CaAl3)3 is Bergman Structure: Mg32(Al,Zn)49 Bergman-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to three equivalent Ca(3), three equivalent Al(1), three equivalent Al(2), and three equivalent Al(3) atoms. All Ba(1)-Ca(3) bond lengths are 3.83 Å. All Ba(1)-Al(1) bond lengths are 3.75 Å. All Ba(1)-Al(2) bond lengths are 3.70 Å. All Ba(1)-Al(3) bond lengths are 3.96 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Ca(2), one Al(2), three equivalent Al(1), and six equivalent Al(4) atoms. The Ba(2)-Ca(2) bond length is 3.60 Å. The Ba(2)-Al(2) bond length is 3.41 Å. All Ba(2)-Al(1) bond lengths are 3.36 Å. All Ba(2)-Al(4) bond lengths are 3.49 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ca(3), three equivalent Ca(2), three equivalent Al(4), three equivalent Al(5), and six equivalent Al(3) atoms. The Ca(1)-Ca(3) bond length is 3.46 Å. All Ca(1)-Ca(2) bond lengths are 3.55 Å. All Ca(1)-Al(4) bond lengths are 3.26 Å. All Ca(1)-Al(5) bond lengths are 3.40 Å. All Ca(1)-Al(3) bond lengths are 3.36 Å. In the second Ca site, Ca(2) is bonded in a 16-coordinate geometry to one Ba(2), three equivalent Ca(1), three equivalent Al(3), three equivalent Al(5), and six equivalent Al(4) atoms. All Ca(2)-Al(3) bond lengths are 3.27 Å. All Ca(2)-Al(5) bond lengths are 3.41 Å. All Ca(2)-Al(4) bond lengths are 3.35 Å. In the third Ca site, Ca(3) is bonded in a 14-coordinate geometry to three equivalent Ba(1), one Ca(1), one Al(1), three equivalent Al(2), and six equivalent Al(3) atoms. The Ca(3)-Al(1) bond length is 3.53 Å. All Ca(3)-Al(2) bond lengths are 3.37 Å. All Ca(3)-Al(3) bond lengths are 3.40 Å. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to three equivalent Ba(1), three equivalent Ba(2), one Ca(3), and three equivalent Al(4) atoms. All Al(1)-Al(4) bond lengths are 2.72 Å. In the second Al site, Al(2) is bonded in a 10-coordinate geometry to one Ba(2), three equivalent Ba(1), three equivalent Ca(3), and three equivalent Al(3) atoms. All Al(2)-Al(3) bond lengths are 2.69 Å. In the third Al site, Al(3) is bonded to one Ba(1), one Ca(2), two equivalent Ca(1), two equivalent Ca(3), one Al(2), one Al(5), and four equivalent Al(3) atoms to form distorted AlBaCa5Al6 cuboctahedra that share corners with two equivalent Al(5)Ca6Al6 cuboctahedra, corners with four equivalent Al(3)BaCa5Al6 cuboctahedra, edges with two equivalent Al(3)BaCa5Al6 cuboctahedra, faces with three equivalent Al(5)Ca6Al6 cuboctahedra, and faces with eight equivalent Al(3)BaCa5Al6 cuboctahedra. The Al(3)-Al(5) bond length is 2.85 Å. There are two shorter (2.81 Å) and two longer (3.00 Å) Al(3)-Al(3) bond lengths. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to two equivalent Ba(2), one Ca(1), two equivalent Ca(2), one Al(1), one Al(5), and four equivalent Al(4) atoms. The Al(4)-Al(5) bond length is 2.84 Å. There are two shorter (2.82 Å) and two longer (2.99 Å) Al(4)-Al(4) bond lengths. In the fifth Al site, Al(5) is bonded to three equivalent Ca(1), three equivalent Ca(2), three equivalent Al(3), and three equivalent Al(4) atoms to form AlCa6Al6 cuboctahedra that share corners with six equivalent Al(3)BaCa5Al6 cuboctahedra, edges with six equivalent Al(5)Ca6Al6 cuboctahedra, and faces with nine equivalent Al(3)BaCa5Al6 cuboctahedra.