Determination of Ti coordination from pre-edge peaks in TiK-edge XANES

The pre-edge peaks of Ti $K$-edge XANES have been widely used in determining Ti coordination in amorphous materials and in crystals despite the fact that coordination is not the only factor that the pre-edge peaks depend on. This work thoroughly examines the dependence of the shape of Ti $K$ pre-edge peaks on various geometrical parameters (coordination, symmetry, Ti-O bond length and bond angle) using distorted rutile $\mathrm{Ti}{\mathrm{O}}_{2}$ as models. We conclude that the greatest impact on the pre-edge peaks arises from a reduction in Ti-O bond length, although other parameters such as symmetry and coordination all have some effect.