Ba2ErCuZn2O7 crystallizes in the orthorhombic Pmmm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. Er(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Cu(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(4) atoms. Zn(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted corner-sharing ZnO5 square pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Zn(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Zn(1) atoms. In the third O site, O(3) is bonded to four equivalent Ba(1), one Cu(1), and one Zn(1) atom to form distorted OBa4ZnCu octahedra that share corners with four equivalent O(4)Ba4Cu2 octahedra, corners with five equivalent O(3)Ba4ZnCu octahedra, edges with four equivalent O(3)Ba4ZnCu octahedra, and faces with two equivalent O(4)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-65°. In the fourth O site, O(4) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with two equivalent O(4)Ba4Cu2 octahedra, corners with eight equivalent O(3)Ba4ZnCu octahedra, edges with two equivalent O(4)Ba4Cu2 octahedra, and faces with four equivalent O(3)Ba4ZnCu octahedra. The corner-sharing octahedral tilt angles range from 0-65°.
Ba2ErCuZn2O7 crystallizes in the orthorhombic Pmmm space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. Both Ba(1)-O(1) bond lengths are 3.07 Å. Both Ba(1)-O(2) bond lengths are 3.04 Å. Both Ba(1)-O(4) bond lengths are 2.88 Å. All Ba(1)-O(3) bond lengths are 2.81 Å. Er(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Er(1)-O(1) bond lengths are 2.44 Å. All Er(1)-O(2) bond lengths are 2.41 Å. Cu(1) is bonded in a square co-planar geometry to two equivalent O(3) and two equivalent O(4) atoms. Both Cu(1)-O(3) bond lengths are 1.89 Å. Both Cu(1)-O(4) bond lengths are 2.00 Å. Zn(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted corner-sharing ZnO5 square pyramids. The Zn(1)-O(3) bond length is 2.11 Å. Both Zn(1)-O(1) bond lengths are 2.01 Å. Both Zn(1)-O(2) bond lengths are 2.05 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Zn(1) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Er(1), and two equivalent Zn(1) atoms. In the third O site, O(3) is bonded to four equivalent Ba(1), one Cu(1), and one Zn(1) atom to form distorted OBa4ZnCu octahedra that share corners with four equivalent O(4)Ba4Cu2 octahedra, corners with five equivalent O(3)Ba4ZnCu octahedra, edges with four equivalent O(3)Ba4ZnCu octahedra, and faces with two equivalent O(4)Ba4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-65°. In the fourth O site, O(4) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form distorted OBa4Cu2 octahedra that share corners with two equivalent O(4)Ba4Cu2 octahedra, corners with eight equivalent O(3)Ba4ZnCu octahedra, edges with two equivalent O(4)Ba4Cu2 octahedra, and faces with four equivalent O(3)Ba4ZnCu octahedra. The corner-sharing octahedral tilt angles range from 0-65°.