B2Bi2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(2), one O(5), 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(4), and one O(7) atom. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in an octahedral geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Bi(1) and one Bi(2) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one B(2), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one B(2), one Bi(1), and one Bi(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(2) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one B(1), one Bi(1), and one Bi(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one B(2), one Bi(1), and one Bi(2) atom.
B2Bi2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(2), one O(5), and one O(6) atom. The B(1)-O(2) bond length is 1.39 Å. The B(1)-O(5) bond length is 1.35 Å. The B(1)-O(6) bond length is 1.41 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(7) atom. The B(2)-O(3) bond length is 1.39 Å. The B(2)-O(4) bond length is 1.37 Å. The B(2)-O(7) bond length is 1.39 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in an octahedral geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. The Bi(1)-O(1) bond length is 2.04 Å. The Bi(1)-O(2) bond length is 2.14 Å. The Bi(1)-O(3) bond length is 2.24 Å. The Bi(1)-O(4) bond length is 2.20 Å. The Bi(1)-O(6) bond length is 2.20 Å. The Bi(1)-O(7) bond length is 2.24 Å. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Bi(2)-O(1) bond length is 2.12 Å. The Bi(2)-O(3) bond length is 2.54 Å. The Bi(2)-O(4) bond length is 2.60 Å. The Bi(2)-O(5) bond length is 2.15 Å. The Bi(2)-O(6) bond length is 2.66 Å. The Bi(2)-O(7) bond length is 2.44 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Bi(1) and one Bi(2) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one B(2), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one B(2), one Bi(1), and one Bi(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(2) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one B(1), one Bi(1), and one Bi(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one B(2), one Bi(1), and one Bi(2) atom.