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 3-coordinate geometry to one O(1), one O(5), and one O(6) atom. In the second B site, B(2) is bonded in a 1-coordinate geometry to one O(2), 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 a 2-coordinate geometry to one O(5) and two equivalent O(2) atoms. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one B(1) and one Bi(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one B(2), two equivalent Bi(1), one O(2), and one O(7) atom. In the third O site, O(3) is bonded in a single-bond geometry to one B(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one B(2) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one B(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one B(2) and one O(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 3-coordinate geometry to one O(1), one O(5), and one O(6) atom. The B(1)-O(1) bond length is 1.32 Å. The B(1)-O(5) bond length is 2.06 Å. The B(1)-O(6) bond length is 1.09 Å. In the second B site, B(2) is bonded in a 1-coordinate geometry to one O(2), one O(3), one O(4), and one O(7) atom. The B(2)-O(2) bond length is 2.19 Å. The B(2)-O(3) bond length is 1.99 Å. The B(2)-O(4) bond length is 1.35 Å. The B(2)-O(7) bond length is 1.98 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 2-coordinate geometry to one O(5) and two equivalent O(2) atoms. The Bi(1)-O(5) bond length is 1.54 Å. There is one shorter (2.18 Å) and one longer (2.57 Å) Bi(1)-O(2) bond length. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(4) atoms. The Bi(2)-O(1) bond length is 2.05 Å. There is one shorter (2.18 Å) and one longer (2.35 Å) Bi(2)-O(4) bond length. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one B(1) and one Bi(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one B(2), two equivalent Bi(1), one O(2), and one O(7) atom. The O(2)-O(2) bond length is 1.89 Å. The O(2)-O(7) bond length is 1.87 Å. In the third O site, O(3) is bonded in a single-bond geometry to one B(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one B(2) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one B(1) and one Bi(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one B(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one B(2) and one O(2) atom.