fig9

Figure 9. (A) The primitive crystal structures of Ag₃Te₄X (X = W, Ta). Phonon dispersions for (B) Ag₃Te₄W and (C) Ag₄Se₄Ta, respectively, along the high-symmetry points which are defined as Γ (0, 0, 0), X (0, 0.5, 0), M (0.5, 0.5, 0.0), Z (0, 0, 0.5), R (0, 0.5, 0.5), A (0.5, 0.5, 0.5).