Lattice Dynamics and Superconductivity of RuB₂: A First-Principles Study

We report the first-principles linear response calculations on lattice dynamics and electron-phonon coupling (EPC) of superhard material RuB₂. Phonon frequencies and eigenvectors are obtained throughout the whole Brillouin zone. The calculated EPC parameters for the optical phonon modes at Γ indicate that the d electrons of transition metal play the most important role in deciding the superconducting behaviour, and there are sizeable contributions from B p electrons to EPC. Our calculated EPC constant is 0.41, and the estimated superconducting transition temperature T_c is 1.6K using the Coulomb pseudopotential μ*=0.12, in excellent agreement with the