BaSmLaCuO5 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded in a distorted q6 geometry to two equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. Sm(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. La(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Sm(1), and two equivalent La(1) atoms to form OBa2La2Sm2 octahedra that share corners with six equivalent O(1)Ba2La2Sm2 octahedra, corners with eight equivalent O(2)Ba2La2SmCu octahedra, corners with eight equivalent O(3)Ba2LaSm2Cu octahedra, faces with four equivalent O(2)Ba2La2SmCu octahedra, and faces with four equivalent O(3)Ba2LaSm2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(1), one Sm(1), two equivalent La(1), and one Cu(2) atom to form distorted OBa2La2SmCu octahedra that share corners with four equivalent O(1)Ba2La2Sm2 octahedra, corners with five equivalent O(2)Ba2La2SmCu octahedra, corners with eight equivalent O(3)Ba2LaSm2Cu octahedra,  an edgeedge with one O(2)Ba2La2SmCu octahedra, edges with four equivalent O(3)Ba2LaSm2Cu octahedra, faces with two equivalent O(1)Ba2La2Sm2 octahedra, and faces with three equivalent O(2)Ba2La2SmCu octahedra. The corner-sharing octahedral tilt angles range from 0-78°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Sm(1), one La(1), and one Cu(1) atom to form distorted OBa2LaSm2Cu octahedra that share corners with four equivalent O(1)Ba2La2Sm2 octahedra, corners with five equivalent O(3)Ba2LaSm2Cu octahedra, corners with eight equivalent O(2)Ba2La2SmCu octahedra,  an edgeedge with one O(3)Ba2LaSm2Cu octahedra, edges with four equivalent O(2)Ba2La2SmCu octahedra, faces with two equivalent O(1)Ba2La2Sm2 octahedra, and faces with three equivalent O(3)Ba2LaSm2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-78°.
BaSmLaCuO5 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded in a distorted q6 geometry to two equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. Both Ba(1)-O(1) bond lengths are 2.95 Å. All Ba(1)-O(2) bond lengths are 2.98 Å. All Ba(1)-O(3) bond lengths are 3.00 Å. Sm(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Sm(1)-O(1) bond lengths are 2.52 Å. Both Sm(1)-O(2) bond lengths are 2.33 Å. All Sm(1)-O(3) bond lengths are 2.60 Å. La(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Both La(1)-O(1) bond lengths are 2.50 Å. Both La(1)-O(3) bond lengths are 2.37 Å. All La(1)-O(2) bond lengths are 2.66 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Cu(1)-O(3) bond lengths are 1.95 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Cu(2)-O(2) bond lengths are 1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(1), two equivalent Sm(1), and two equivalent La(1) atoms to form OBa2La2Sm2 octahedra that share corners with six equivalent O(1)Ba2La2Sm2 octahedra, corners with eight equivalent O(2)Ba2La2SmCu octahedra, corners with eight equivalent O(3)Ba2LaSm2Cu octahedra, faces with four equivalent O(2)Ba2La2SmCu octahedra, and faces with four equivalent O(3)Ba2LaSm2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(1), one Sm(1), two equivalent La(1), and one Cu(2) atom to form distorted OBa2La2SmCu octahedra that share corners with four equivalent O(1)Ba2La2Sm2 octahedra, corners with five equivalent O(2)Ba2La2SmCu octahedra, corners with eight equivalent O(3)Ba2LaSm2Cu octahedra,  an edgeedge with one O(2)Ba2La2SmCu octahedra, edges with four equivalent O(3)Ba2LaSm2Cu octahedra, faces with two equivalent O(1)Ba2La2Sm2 octahedra, and faces with three equivalent O(2)Ba2La2SmCu octahedra. The corner-sharing octahedral tilt angles range from 0-78°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Sm(1), one La(1), and one Cu(1) atom to form distorted OBa2LaSm2Cu octahedra that share corners with four equivalent O(1)Ba2La2Sm2 octahedra, corners with five equivalent O(3)Ba2LaSm2Cu octahedra, corners with eight equivalent O(2)Ba2La2SmCu octahedra,  an edgeedge with one O(3)Ba2LaSm2Cu octahedra, edges with four equivalent O(2)Ba2La2SmCu octahedra, faces with two equivalent O(1)Ba2La2Sm2 octahedra, and faces with three equivalent O(3)Ba2LaSm2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-78°.