Ba5Al2Ge7 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent Al(1), two equivalent Ge(3), two equivalent Ge(4), and four equivalent Ge(2) atoms to form a mixture of distorted edge and face-sharing BaAl4Ge8 cuboctahedra. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one Al(1), two equivalent Al(2), one Ge(1), one Ge(2), two equivalent Ge(3), two equivalent Ge(4), and two equivalent Ge(6) atoms. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent Ge(1), four equivalent Ge(5), and four equivalent Ge(6) atoms. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to one Al(2), one Ge(1), one Ge(4), two equivalent Ge(5), and four equivalent Ge(6) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(2), four equivalent Ba(1), one Ge(2), one Ge(3), and one Ge(4) atom. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to one Ba(4), four equivalent Ba(2), one Ge(1), one Ge(3), and two equivalent Ge(6) atoms. There are six inequivalent Ge sites. In the first Ge site, Ge(4) is bonded in a 1-coordinate geometry to one Ba(4), two equivalent Ba(1), four equivalent Ba(2), and one Al(1) atom. In the second Ge site, Ge(5) is bonded in a 9-coordinate geometry to two equivalent Ba(4), four equivalent Ba(3), one Ge(1), and two equivalent Ge(6) atoms. In the third Ge site, Ge(6) is bonded in a 9-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), two equivalent Ba(4), one Al(2), one Ge(1), and one Ge(5) atom. In the fourth Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Ba(4), two equivalent Ba(2), two equivalent Ba(3), one Al(2), one Ge(5), and two equivalent Ge(6) atoms. In the fifth Ge site, Ge(2) is bonded in a distorted single-bond geometry to two equivalent Ba(2), four equivalent Ba(1), and one Al(1) atom. In the sixth Ge site, Ge(3) is bonded in a distorted water-like geometry to two equivalent Ba(1), four equivalent Ba(2), one Al(1), and one Al(2) atom.
Ba5Al2Ge7 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent Al(1), two equivalent Ge(3), two equivalent Ge(4), and four equivalent Ge(2) atoms to form a mixture of distorted edge and face-sharing BaAl4Ge8 cuboctahedra. There are two shorter (3.59 Å) and two longer (3.68 Å) Ba(1)-Al(1) bond lengths. Both Ba(1)-Ge(3) bond lengths are 3.53 Å. Both Ba(1)-Ge(4) bond lengths are 3.80 Å. There are two shorter (3.55 Å) and two longer (3.66 Å) Ba(1)-Ge(2) bond lengths. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one Al(1), two equivalent Al(2), one Ge(1), one Ge(2), two equivalent Ge(3), two equivalent Ge(4), and two equivalent Ge(6) atoms. The Ba(2)-Al(1) bond length is 3.83 Å. There is one shorter (3.54 Å) and one longer (3.63 Å) Ba(2)-Al(2) bond length. The Ba(2)-Ge(1) bond length is 3.54 Å. The Ba(2)-Ge(2) bond length is 3.50 Å. There is one shorter (3.48 Å) and one longer (3.90 Å) Ba(2)-Ge(3) bond length. There is one shorter (3.46 Å) and one longer (3.69 Å) Ba(2)-Ge(4) bond length. There is one shorter (3.46 Å) and one longer (3.59 Å) Ba(2)-Ge(6) bond length. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent Ge(1), four equivalent Ge(5), and four equivalent Ge(6) atoms. Both Ba(3)-Ge(1) bond lengths are 3.46 Å. There are two shorter (3.49 Å) and two longer (3.62 Å) Ba(3)-Ge(5) bond lengths. There are two shorter (3.39 Å) and two longer (3.56 Å) Ba(3)-Ge(6) bond lengths. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to one Al(2), one Ge(1), one Ge(4), two equivalent Ge(5), and four equivalent Ge(6) atoms. The Ba(4)-Al(2) bond length is 3.54 Å. The Ba(4)-Ge(1) bond length is 3.50 Å. The Ba(4)-Ge(4) bond length is 3.75 Å. There is one shorter (3.48 Å) and one longer (3.68 Å) Ba(4)-Ge(5) bond length. There are two shorter (3.43 Å) and two longer (3.89 Å) Ba(4)-Ge(6) bond lengths. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(2), four equivalent Ba(1), one Ge(2), one Ge(3), and one Ge(4) atom. The Al(1)-Ge(2) bond length is 2.50 Å. The Al(1)-Ge(3) bond length is 2.47 Å. The Al(1)-Ge(4) bond length is 2.48 Å. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to one Ba(4), four equivalent Ba(2), one Ge(1), one Ge(3), and two equivalent Ge(6) atoms. The Al(2)-Ge(1) bond length is 2.62 Å. The Al(2)-Ge(3) bond length is 2.47 Å. Both Al(2)-Ge(6) bond lengths are 2.54 Å. There are six inequivalent Ge sites. In the first Ge site, Ge(4) is bonded in a 1-coordinate geometry to one Ba(4), two equivalent Ba(1), four equivalent Ba(2), and one Al(1) atom. In the second Ge site, Ge(5) is bonded in a 9-coordinate geometry to two equivalent Ba(4), four equivalent Ba(3), one Ge(1), and two equivalent Ge(6) atoms. The Ge(5)-Ge(1) bond length is 2.64 Å. Both Ge(5)-Ge(6) bond lengths are 2.58 Å. In the third Ge site, Ge(6) is bonded in a 9-coordinate geometry to two equivalent Ba(2), two equivalent Ba(3), two equivalent Ba(4), one Al(2), one Ge(1), and one Ge(5) atom. The Ge(6)-Ge(1) bond length is 2.67 Å. In the fourth Ge site, Ge(1) is bonded in a 9-coordinate geometry to one Ba(4), two equivalent Ba(2), two equivalent Ba(3), one Al(2), one Ge(5), and two equivalent Ge(6) atoms. In the fifth Ge site, Ge(2) is bonded in a distorted single-bond geometry to two equivalent Ba(2), four equivalent Ba(1), and one Al(1) atom. In the sixth Ge site, Ge(3) is bonded in a distorted water-like geometry to two equivalent Ba(1), four equivalent Ba(2), one Al(1), and one Al(2) atom.