Ab initio structure determination of SrBi2OB4O9 by powder X-ray/neutron diffraction and NMR spectroscopy

SrBi 2 OB 4 O 9 is a novel centrosymmetric borate oxide forming in the SrO–Bi 2 O 3 –B 2 O 3 system. Its crystal structure has been determined ab initio from high-resolution X-ray and neutron powder diffraction data with the help of 11 B MAS-NMR data. SrBi 2 OB 4 O 9 crystallizes with a triclinic unit-cell with a =6.8657(1) Å, b =9.7976(1) Å, c =6.8148(1) Å, α =109.1270(8)°, β =101.8971(8)°, γ =96.1445(8)°, V =416.17(1) Å 3 , Z =2, space group P-1. Its structure consists of Bi 2 O 4+ layers alternating along the b axis with SrB 4 O 9 4− layers containing isolated B 4 O 9 6− (〈2 Δ 〉 Δ ) tetraborate anions.