Brookite, TiO2, synthesized by hydrothermal processing of a titanium oxide gel was shown by powder X-ray and single-crystal electron diffraction to consist of very well ordered single crystals. The titanium coupling constant determined from Ti-47,Ti-49 NMR spectroscopy is intermediate between the coupling constants for anatase and rutile. O-17 NMR spectroscopy locates the two crystallographically inequivalent oxygen atoms in brookite. Electron diffraction and microscopy and Ti NMR show that a comparison sample of naturally occurring brookite has many more defects.
Bastow, T. J., Doran, G., & Whitfield, H. J. (2000). Electron Diffraction and Ti-47,Ti-49 and O-17 Nmr Studies of Natural and Synthetic Brookite. Chemistry of Materials, 12(2), 436-439. https://doi.org/10.1021/cm990486m