Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (11): 1331-1336.doi: 10.1016/S1872-1508(06)60066-1

• ARTICLE • Previous Articles     Next Articles

First Principles Analysis for Electronic Structure on LaNi5-xCox Alloys

LI Li;WU Feng;CHEN Shi;CHEN Ren-Jie   

  1. School of Chemical Engineering and Environment, Beijing Institute of Technology; National Development Center of Hi-Tech Green Materials, Beijing 100081, P. R. China; Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
  • Received:2006-04-19 Revised:2006-06-16 Published:2006-11-06
  • Contact: WU Feng

Abstract: Electronic structures of LaNi5−xCox (x=0, 0.5, 1) hydrogen-storage alloy have been studied theoretically using the method of total energy based on the density functional theory (DFT). The plane wave function was selected as the basis set in combination with the ultrasoft pseudopotential technology. Crystal structure, energy band structure, electronic density of states, and Mulliken density of LaNi5−xCox were calculated. The results indicated that valence electrons were mainly fastened around fermi energy (EF) and EF moved toward the direction of lower energy with the increase of the Co content. According to the analysis of Mulliken overlap populations, the numerical values of the bonds between Ni3g—Ni3g and Ni2c—Ni2c decreased. It showed that Co doping let to the decrease in the bond energy between Ni—Ni. However, the values on the bond between La—Ni increased and the relevant bond energy increased.

Key words: LaNi4.5Co0.5, LaNi4Co, Electronic structure, Density functional theory, Geometrical structure