Comment on: Ab initio calculations of B2 type RHg (R = Ce,Pr,Eu and Gd) intermetallic compounds

Abstract

In a recent article by Devi et al. [Eur. Phys. J. B 87, 268 (2014)], the structural, electronic, elastic and some thermal properties of B2 type RHg (R = Ce, Pr, Eu and Gd) intermetallic compounds have been studied by ab initio calculations. After the study of their article I found that there are some mistakes in predicted crystal density, longitudinal, transverse and average elastic wave velocities, and Debye temperature data. The crystal density has been found multiplied per 4. Also the longitudinal, transverse and average elastic wave velocities and Debye temperature are different from my reexamined values (all results represented by Devi et al. have been found divided per 2). Although these small mistakes do not influence their conclusion, it is better to correct them. In the present work, I reexamined all data again by using the right formulas, based on the lattice parameters and the elastic constants obtained in the work of Devi et al.