A study on the correlation between electronic structures of RENi5 and their hydrides and hydrogen absorption properties Original Research Article

The electronic structures of RENi5 (RE=La, Ce, Pr, Nd) and their hydrides were investigated by the SCC-DV-Xα (Self-Consistent-Charge Discrete Variational Xα) method. The results show that the stabilities of RENi5 hydrides are related to the charge transferred to the hydrogen atom, and decrease with increase of the transferred charge. There is a strong orbital interaction between the 3d orbit in the Ni atom and the 4f orbit in the RE atom, which is weakened when the hydride is formed. The equilibrium plateau pressure of RENi5 rises with lowering of the Fermi energy of the hydride.