On the choice of exchange and correlation potentials among various hybrid and GGA potentials in deducing momentum densities of magnetocaloric La-Ni-Co system

Electronic structure and momentum densities of LaNi4.5Co0.5 using various approximations of density functional theory and hybrid models are presented. The role of different models in reproducing energy bands and momentum densities are compared and analysed. It is seen that overall topology of energy bands and density of states are similar, except some fine structures. The sensitivity of different exchange and correlation potentials in reproducing the Compton profiles is discussed. Significant charge transfer from La and Co to Ni as derived from Mulliken’s population analysis depicts dominance of ionic bond in the studied magnetocaloric system.