Comment on “Structural, electronic, elastic, optical and thermodynamic properties of copper halides CuCl, CuBr and their ternary alloys CuCl1−xBrx (0.0 ≤ x ≤ 1.0) using full-potential linear muffin-tin orbital (FP-LMTO) method”[Optik 127 (2016) 4559–4573

Abstract

Kamel et al. (2016) [1] have recently published a paper in Optik 127 (2016) 4559–4573. They have studied several interesting properties, such as: structural, elastic, electronic, optical and thermodynamic properties of copper halides (CuCl, CuBr and their ternary alloys CuCl1−xBrx (0.0≤x≤1.0)) using full-potential linear muffin-tin orbital (FP-LMTO) method. After carefully reading the paper of Kamel et al. (2016), it is observed that the algebraic values of the longitudinal (vl), transverse (vt) and average (vm) wave velocities, and also that of the Debye temperature θD, of CuX (X=Cl, Br) binary compounds obtained in the paper Kamel et al. (2016) [1] are not correctly calculated. Although this mistake has no influence on the conclusion of the paper Kamel et al. (2016) [1], I think, that is better to correct the numerical values of the previous quantities, which can be reused in the future by other researchers, perhaps for comparison or for other object.In the present work, I recalculate the correct numerical values of the longitudinal (vl), transverse (vt) and average (vm) wave velocities, and the Debye temperature θD, of CuX (X=Cl, Br) compounds, using the lattice parameters and the elastic moduli obtained in the original work of Kamel et al. (2016) [1].