Structural, electronic and thermodynamic properties of ZrCo and ZrCoH3: A first-principles study

The ZrCo intermetallic is considered to be strategically important for hydrogen isotope storage and its use in the International Thermonuclear Experimental Reactor (ITER) system. Here we report the structural, electronic and thermodynamic properties of ZrCo and ZrCoH3 using the first-principles approach. The calculations are performed using a plane-wave based pseudo-potential approach under the framework of spin-polarized density-functional theory. The ground state properties like lattice constants, bulk moduli, and enthalpy of formation have been determined by optimizing the atomic and electronic structure of ZrCo and ZrCoH3 compounds. From the total energy calculations, the enthalpy of formation of ZrCoH3 from ZrCo is estimated to be −91 kJ/mol H2 at 0 K. Both lattice parameters and formation energy are found to be in good agreement with their corresponding experimental values. The nature of chemical bonding in ZrCo and ZrCoH3 has been analyzed from the electronic density of states spectrum of the constituent materials.