Abstract: The equilibrium structures and electronic structure of LaNi 5-x Ga x (x=0, 0.5, 1.0) compounds have been investigated by all-electron calculations. Based on the full geometry optimization, the densities of states and electron densities of LaNi 5-x Ga x are plotted and analyzed. It is clear that the substitution of Ga at the Ni site leads to a progressive filling of the Ni-d bands, the ionic interaction between Ni and Ni, with Ga plays a dominant role in the stability of LaNi 5-x Ga x compounds. The smaller the shift of E F toward higher energy region, the more stable thecompounds will be. The increased contribution of the Ni-d-Ga-d interactions near E F and the low energy metal-gallium bonding bands indicate that the compounds become more stable. The results are compared with experimental data and discussed in light of previous studies.

Key words: FLAPW and GGA, LaNi 5-x Ga x, Intermetallic compound, Electronic structure