Cu2Zn(BO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(6), and two equivalent O(5) atoms. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to one O(1), one O(4), and two equivalent O(3) atoms. Zn(1) is bonded to one O(1), one O(2), one O(5), and two equivalent O(4) atoms to form corner-sharing ZnO5 square pyramids. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(6) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(3), one O(5), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(4) is bonded to one Cu(1), one Cu(2), and two equivalent Zn(1) atoms to form corner-sharing OZn2Cu2 tetrahedra. In the second O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Cu(1), one Zn(1), and one B(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Cu(1), one B(1), and one B(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Cu(2), one Zn(1), and one B(1) atom. In the fifth O site, O(2) is bonded in a distorted T-shaped geometry to one Cu(1), one Zn(1), and one B(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Cu(2) and one B(2) atom.
Cu2Zn(BO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(6), and two equivalent O(5) atoms. The Cu(1)-O(2) bond length is 2.00 Å. The Cu(1)-O(4) bond length is 1.89 Å. The Cu(1)-O(6) bond length is 2.08 Å. There is one shorter (1.94 Å) and one longer (2.59 Å) Cu(1)-O(5) bond length. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to one O(1), one O(4), and two equivalent O(3) atoms. The Cu(2)-O(1) bond length is 1.98 Å. The Cu(2)-O(4) bond length is 1.93 Å. There is one shorter (1.97 Å) and one longer (1.98 Å) Cu(2)-O(3) bond length. Zn(1) is bonded to one O(1), one O(2), one O(5), and two equivalent O(4) atoms to form corner-sharing ZnO5 square pyramids. The Zn(1)-O(1) bond length is 2.09 Å. The Zn(1)-O(2) bond length is 2.07 Å. The Zn(1)-O(5) bond length is 2.15 Å. There is one shorter (2.06 Å) and one longer (2.08 Å) Zn(1)-O(4) bond length. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(6) atom. The B(1)-O(1) bond length is 1.35 Å. The B(1)-O(2) bond length is 1.36 Å. The B(1)-O(6) bond length is 1.44 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(3), one O(5), and one O(6) atom. The B(2)-O(3) bond length is 1.36 Å. The B(2)-O(5) bond length is 1.37 Å. The B(2)-O(6) bond length is 1.41 Å. There are six inequivalent O sites. In the first O site, O(4) is bonded to one Cu(1), one Cu(2), and two equivalent Zn(1) atoms to form corner-sharing OZn2Cu2 tetrahedra. In the second O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Cu(1), one Zn(1), and one B(2) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to one Cu(1), one B(1), and one B(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Cu(2), one Zn(1), and one B(1) atom. In the fifth O site, O(2) is bonded in a distorted T-shaped geometry to one Cu(1), one Zn(1), and one B(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Cu(2) and one B(2) atom.