TY - JOUR T1 - Elastic Properties and Phonon Dispersion of bcc Vanadium under Pressure from First Principles AU - Zhang , L.-Q. AU - Cheng , Y. AU - Niu , Z.-W. JO - Journal of Atomic and Molecular Sciences VL - 1 SP - 81 EP - 94 PY - 2014 DA - 2014/05 SN - 5 DO - http://doi.org/10.4208/jams.072513.101413a UR - https://global-sci.org/intro/article_detail/jams/8303.html KW - vanadium, elastic properties, phonon dispersion, density functional theory. AB -

We investigate the elastic properties and phonon dispersion of the body-centered cubic structure vanadium $(V)$ under pressure by using the generalized gradient approximation (GGA). Our elastic constants of $V$ at zero pressure and zero temperature are in good agreement with the available experimental data and other theoretical data. The pressure dependences of bulk modulus $B$ and its pressure derivative $B',$ shear modulus $G,$ elastic Debye temperature $\Theta_E,$ elastic anisotropy factor $A,$ Poisson ratios $σ$ and Kleinmann parameter $ζ$ are also presented. An analysis for the calculated elastic constants has been made to reveal the mechanical unstability of $V$ up to 100 GPa. For the phonon dispersions of $V,$ it is easily seen that the phonon frequencies increase as the volume decreases, the phonon mode linked to a Kohn anomaly has softened to negative values.