Sr2(AgAl)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to two equivalent Ag(1), four equivalent Ag(2), four equivalent Al(1), and eight equivalent Al(2) atoms. In the second Sr site, Sr(2) is bonded in a 18-coordinate geometry to two equivalent Ag(2), four equivalent Ag(1), four equivalent Ag(3), and eight equivalent Al(2) atoms. There are three inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 7-coordinate geometry to one Sr(1), two equivalent Sr(2), two equivalent Ag(3), and four equivalent Al(2) atoms. In the second Ag site, Ag(2) is bonded in a 9-coordinate geometry to one Sr(2), two equivalent Sr(1), two equivalent Al(1), and four equivalent Al(2) atoms. In the third Ag site, Ag(3) is bonded to four equivalent Sr(2), four equivalent Ag(1), and four equivalent Al(2) atoms to form AgSr4Al4Ag4 cuboctahedra that share corners with four equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, corners with four equivalent Al(1)Sr4Al4Ag4 cuboctahedra, edges with two equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, and faces with two equivalent Ag(3)Sr4Al4Ag4 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Sr(1), four equivalent Ag(2), and four equivalent Al(2) atoms to form distorted AlSr4Al4Ag4 cuboctahedra that share corners with four equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, corners with four equivalent Al(1)Sr4Al4Ag4 cuboctahedra, edges with two equivalent Al(1)Sr4Al4Ag4 cuboctahedra, and faces with two equivalent Al(1)Sr4Al4Ag4 cuboctahedra. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ag(3), two equivalent Ag(1), two equivalent Ag(2), one Al(1), and two equivalent Al(2) atoms.
Sr2(AgAl)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 6-coordinate geometry to two equivalent Ag(1), four equivalent Ag(2), four equivalent Al(1), and eight equivalent Al(2) atoms. Both Sr(1)-Ag(1) bond lengths are 3.16 Å. All Sr(1)-Ag(2) bond lengths are 3.23 Å. All Sr(1)-Al(1) bond lengths are 3.55 Å. All Sr(1)-Al(2) bond lengths are 3.62 Å. In the second Sr site, Sr(2) is bonded in a 18-coordinate geometry to two equivalent Ag(2), four equivalent Ag(1), four equivalent Ag(3), and eight equivalent Al(2) atoms. Both Sr(2)-Ag(2) bond lengths are 3.29 Å. All Sr(2)-Ag(1) bond lengths are 3.30 Å. All Sr(2)-Ag(3) bond lengths are 3.55 Å. All Sr(2)-Al(2) bond lengths are 3.59 Å. There are three inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 7-coordinate geometry to one Sr(1), two equivalent Sr(2), two equivalent Ag(3), and four equivalent Al(2) atoms. Both Ag(1)-Ag(3) bond lengths are 2.86 Å. All Ag(1)-Al(2) bond lengths are 2.71 Å. In the second Ag site, Ag(2) is bonded in a 9-coordinate geometry to one Sr(2), two equivalent Sr(1), two equivalent Al(1), and four equivalent Al(2) atoms. Both Ag(2)-Al(1) bond lengths are 2.78 Å. All Ag(2)-Al(2) bond lengths are 2.74 Å. In the third Ag site, Ag(3) is bonded to four equivalent Sr(2), four equivalent Ag(1), and four equivalent Al(2) atoms to form AgSr4Al4Ag4 cuboctahedra that share corners with four equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, corners with four equivalent Al(1)Sr4Al4Ag4 cuboctahedra, edges with two equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, and faces with two equivalent Ag(3)Sr4Al4Ag4 cuboctahedra. All Ag(3)-Al(2) bond lengths are 2.83 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Sr(1), four equivalent Ag(2), and four equivalent Al(2) atoms to form distorted AlSr4Al4Ag4 cuboctahedra that share corners with four equivalent Ag(3)Sr4Al4Ag4 cuboctahedra, corners with four equivalent Al(1)Sr4Al4Ag4 cuboctahedra, edges with two equivalent Al(1)Sr4Al4Ag4 cuboctahedra, and faces with two equivalent Al(1)Sr4Al4Ag4 cuboctahedra. All Al(1)-Al(2) bond lengths are 2.85 Å. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Ag(3), two equivalent Ag(1), two equivalent Ag(2), one Al(1), and two equivalent Al(2) atoms. There is one shorter (2.74 Å) and one longer (2.80 Å) Al(2)-Al(2) bond length.