The compositional series CsTixAl1-xSi2O6+x/2, 0 less than or equal to x less than or equal to 1, was investigated using X-ray absorption and Raman spectroscopy. The data indicate the formation of TiO5 edge-sharing polyhedra at relatively low Ti concentrations (x = 0.3). The presence of TiO5 polyhedra in the compositional series is evident from the intensity and energy value of characteristic preedge features in the near-edge structure of the X-ray absorption spectra (XANES). The edge-sharing geometry of the TiO5 polyhedra is determined by the analysis of the extended X-ray absorption fine structure (EXAFS) that indicates short (3.0 Angstrom) Ti-Ti interatomic distances. The appearance of features in the Raman spectra at 645 and 717 cm(-1) also support the existence of edge-sharing Ti polyhedra at low levels of Ti substitution. The EXAFS and Raman results suggest a nonrandom pairing of TiO5 polyhedra on symmetrically equivalent sites and the formation of edge-sharing relationship between adjacent TiO5 polyhedra.