“…3b) are similar, and systematic shifts are observed in the positions of some lines depending on the changes in the ratio of cations. The Raman spectra clearly show a two-mode behavior [30]: the lines of GeO 4 and VO 4 are separated from each other, and the (V/Ge)O 4 tetrahedra exhibit a quasi-independent behavior. In the Raman spectra of BiCaLa 3 (GeO 4 ) 3 O, the strongest line of 770 cm À 1 is due to the totally symmetric stretching vibration Table 2 Atomic coordinates and isotropic displacement parameters (U iso  100, (Å 2 )) for BiCa 4 À x La x (VO 4 ) 3 À x (GeO 4 ) x O, x¼ 1-3. weakly on the ratio of Ge:V in the considered solid solutions, and the shift does not exceed 5 cm À 1 .…”