Correlation between the compressibility and absorption properties of hydrogen in some AB5 Haucke compounds

In this paper, we present the results of ab initio band structure calculations based on the local approximation of the density functional theory for several AB5 compounds: YNi5, LaNi5, LaCu5 and some substituted compounds such as: LaNi4.5Al0.5LaNi4Al, LaNi4Cu, LaNi4.5Ge0.5, LaNi4.5Sn0.5. The bulk moduli obtained by total energy minimizations are in satisfactory agreement with available experimental data . These results are used, in conjunction with electronic features such as band filling and Fermi energy characteristics, to discuss the relationship between compressibilities, electronic and H - absorption properties in Haucke compounds. (authors)