GaAl4Sb5 is Lavarevi\'{c}ite-like structured and crystallizes in the orthorhombic Imm2 space group. Ga(1) is bonded to two equivalent Sb(1) and two equivalent Sb(2) atoms to form GaSb4 tetrahedra that share corners with two equivalent Ga(1)Sb4 tetrahedra, corners with two equivalent Al(2)Sb4 tetrahedra, and corners with eight equivalent Al(1)Sb4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Sb(1), one Sb(3), and two equivalent Sb(2) atoms to form AlSb4 tetrahedra that share corners with three equivalent Al(1)Sb4 tetrahedra, corners with four equivalent Ga(1)Sb4 tetrahedra, and corners with five equivalent Al(2)Sb4 tetrahedra. In the second Al site, Al(2) is bonded to one Sb(2) and three equivalent Sb(3) atoms to form AlSb4 tetrahedra that share  a cornercorner with one Ga(1)Sb4 tetrahedra, corners with five equivalent Al(1)Sb4 tetrahedra, and corners with six equivalent Al(2)Sb4 tetrahedra. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent Ga(1) and two equivalent Al(1) atoms to form SbAl2Ga2 tetrahedra that share corners with two equivalent Sb(1)Al2Ga2 tetrahedra, corners with two equivalent Sb(3)Al4 tetrahedra, and corners with eight equivalent Sb(2)Al3Ga tetrahedra. In the second Sb site, Sb(2) is bonded to one Ga(1), one Al(2), and two equivalent Al(1) atoms to form SbAl3Ga tetrahedra that share corners with three equivalent Sb(2)Al3Ga tetrahedra, corners with four equivalent Sb(1)Al2Ga2 tetrahedra, and corners with five equivalent Sb(3)Al4 tetrahedra. In the third Sb site, Sb(3) is bonded to one Al(1) and three equivalent Al(2) atoms to form SbAl4 tetrahedra that share  a cornercorner with one Sb(1)Al2Ga2 tetrahedra, corners with five equivalent Sb(2)Al3Ga tetrahedra, and corners with six equivalent Sb(3)Al4 tetrahedra.
GaAl4Sb5 is Lavarevi\'{c}ite-like structured and crystallizes in the orthorhombic Imm2 space group. Ga(1) is bonded to two equivalent Sb(1) and two equivalent Sb(2) atoms to form GaSb4 tetrahedra that share corners with two equivalent Ga(1)Sb4 tetrahedra, corners with two equivalent Al(2)Sb4 tetrahedra, and corners with eight equivalent Al(1)Sb4 tetrahedra. Both Ga(1)-Sb(1) bond lengths are 2.70 Å. Both Ga(1)-Sb(2) bond lengths are 2.70 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Sb(1), one Sb(3), and two equivalent Sb(2) atoms to form AlSb4 tetrahedra that share corners with three equivalent Al(1)Sb4 tetrahedra, corners with four equivalent Ga(1)Sb4 tetrahedra, and corners with five equivalent Al(2)Sb4 tetrahedra. The Al(1)-Sb(1) bond length is 2.70 Å. The Al(1)-Sb(3) bond length is 2.70 Å. Both Al(1)-Sb(2) bond lengths are 2.70 Å. In the second Al site, Al(2) is bonded to one Sb(2) and three equivalent Sb(3) atoms to form AlSb4 tetrahedra that share  a cornercorner with one Ga(1)Sb4 tetrahedra, corners with five equivalent Al(1)Sb4 tetrahedra, and corners with six equivalent Al(2)Sb4 tetrahedra. The Al(2)-Sb(2) bond length is 2.70 Å. All Al(2)-Sb(3) bond lengths are 2.70 Å. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent Ga(1) and two equivalent Al(1) atoms to form SbAl2Ga2 tetrahedra that share corners with two equivalent Sb(1)Al2Ga2 tetrahedra, corners with two equivalent Sb(3)Al4 tetrahedra, and corners with eight equivalent Sb(2)Al3Ga tetrahedra. In the second Sb site, Sb(2) is bonded to one Ga(1), one Al(2), and two equivalent Al(1) atoms to form SbAl3Ga tetrahedra that share corners with three equivalent Sb(2)Al3Ga tetrahedra, corners with four equivalent Sb(1)Al2Ga2 tetrahedra, and corners with five equivalent Sb(3)Al4 tetrahedra. In the third Sb site, Sb(3) is bonded to one Al(1) and three equivalent Al(2) atoms to form SbAl4 tetrahedra that share  a cornercorner with one Sb(1)Al2Ga2 tetrahedra, corners with five equivalent Sb(2)Al3Ga tetrahedra, and corners with six equivalent Sb(3)Al4 tetrahedra.