A Study on the Correlation between Electronic Structure and Bond Character For LaNi_5 Alloy and Its Hydride

摘要

The bonding manner between hydrogen and alloying elements in LaNi_5 alloy and roles of hydride forming and non-forming elements in LaNi_5 hydride have be investigated by the Self-Consistent-Charge Discrete Variational X_(alpha) method. In LaNi_5 hydride, hydrogen does not bond with La atom directly, which causes La atom to move outwards and the expanding along a axis larger than c axis. Hls orbit hybrids with Ni4p orbit and forms weak covalence bond. The weak bond is favorable for hydrogen desorbed. There is a non-localized bond between Ni and La atom, but the bond is weakened with hydrogen desorbed.