BiAlO3 crystallizes in the orthorhombic Pnma space group. Al(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AlO4 tetrahedra that share corners with eight equivalent Bi(1)O6 octahedra and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-87°. Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted BiO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and corners with eight equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 64-70°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Al(1) and two equivalent Bi(1) atoms.
BiAlO3 crystallizes in the orthorhombic Pnma space group. Al(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AlO4 tetrahedra that share corners with eight equivalent Bi(1)O6 octahedra and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-87°. Both Al(1)-O(1) bond lengths are 1.76 Å. There is one shorter (1.83 Å) and one longer (1.85 Å) Al(1)-O(2) bond length. Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted BiO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and corners with eight equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 64-70°. Both Bi(1)-O(2) bond lengths are 2.78 Å. There are two shorter (2.31 Å) and two longer (2.33 Å) Bi(1)-O(1) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Al(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Al(1) and two equivalent Bi(1) atoms.