Very recently, Parosh et al. [1] report a theoretical results on many physical properties of NaBaX3 (X = Cl, Br, and I) perovskite materials. Our examination of the paper [1] shows that some data are not calculated correctly, especially these of the longitudinal (vl), transverse (vt) and mean (vm) sound velocities, Debye temperature (θD), and minimum thermal conductivity (kmin). Furthermore, some other inaccuracies have been found, notably: the expression of the formula used to calculate the Debye temperature (θD), in the trend of θD as a function of temperature, and in the Dulong–Petit limit for the heat capacity CV. In this paper, we purpose to correct the expression of the formula used to calculate θD, as well as to correct the values of vl, vt, vm, θD, and kmin for NaBaX3 (X = Cl, Br, and I) compounds, using the lattice constants (a) and the elastic constants (Cij) obtained by Parosh et al. [1].
