Ab-initio calculation of electronic structure and electric field gradients in HfAl2 and ZrAl2 Laves phases

A detailed theoretical study of the structure, electronic properties and electric field gradients (EFG) of the HfAl2 and ZrAl2 Laves phases is presented. Using all-electron augmented plane waves plus local orbitals (APW + lo) formalism, the equilibrium volumes, bulk moduli and EFGs for the two compounds are calculated. The obtained results are compared with the available experimental and theoretical data. Better agreement with the experimental data is found by employing supercell calculations with Ta and Cd impurities.