Electronic structure and energetics of LaNi5, alpha-La2Ni10H and beta-La2Ni10H14

The electronic structure and energetics of LaNi5, its hydrogen solution (al pha-La2Ni10H) and its hydride (beta-La2Ni10H14) were investigated by means of the tight-binding linear muffin-tin orbital method within the atomic sph ere approximation (TB-LMTO-ASA). Preferred site occupation of the absorbed hydrogen atoms was investigated in terms of the charge density of the inter stitial sites and the total energy, both of which indicate that the 6m site in the P6/mmm symmetry is the most preferred. A negative heat of formation of La2Ni10H14 was obtained after optimising the kinetic energy of the elec trons outside the atomic spheres and the interstitial sphere radii. (C) 199 8 Elsevier Science S.A. All rights reserved.