where each phonon frequency of q wave vector at jth phonon band index is indicated by ω qj and ℏ is the reduced Plank's constant . Table The G values of A 6 MO 6 materials are significantly higher than that of BaCuF 6 . Thus, this can be the main reason for having considerably lower θ D in BaCuF 6 compared to the other three materials. It is clear from Fig. that the C v of BaCuF 6 is much smaller than that of the A 6 MO 6 materials. The C v of BaCuF 6 is 176.15 JK -1 mol -1 , whereas C v > 1100 JK -1 mol -1 for A 6 MO 6 materials at 300 K temperature. We also investigated the phonon dispersion of the spintronic materials as shown in Fig. . It evidences that those materials are dynamically stable at 0 K temperature as there are no imaginary frequencies in the plots.