Elastic properties, Debye temperature, density of states and electron–phonon coupling of ZrB12 under pressure

The structural parameters, elastic constants and the electronic density of states of ZrB12 under pressure are determined using first-principles calculations with plane-wave pseudopotential density functional theory, within the generalized gradient approximation. From the elastic constants the elastic parameters and Debye temperature were calculated. They increase as the pressure is increased. The density of states at the Fermi level decreases as pressure is increased, changing from 0.576 to 0.515. Using the Debye temperature and the McMillan equation, the electron–phonon coupling constant was obtained as a function of pressure. It is found that the electron–phonon coupling constant is proportional to the logarithm of the ratio between the value of the Debye temperature and the value of the superconducting critical temperature.