Elastic constants and anisotropy of RuB(2) under pressure

The structural, elastic constants and anisotropy of RuB(2) under pressure are investigated by first-principles calculations based on the plane wave pseudopotential density functional theory method within the local density approximation (LDA) as well as the generalized gradient approximation (GGA) for exchange and correlation. The results accord well with the available experimental and other theoretical data. The elastic constants, elastic anisotropy, and Debye temperature circle minus as a function of pressure are presented. It is concluded that RuB(2) is brittle in nature at low pressure, whereas it becomes ductile at higher pressures. An analysis for the calculated elastic constant has been made to reveal the mechanical stability of RuB(2) up to 100 GPa.