First-principles calculation on λ -MnO_2 and LiMn_2O_4

摘要

The difference onsMnO_2 and spinel LiMn_2O_4 electronic structure has been probed by this paper with the MS CASTEP package based on density functional theory (DFT).The λ -MnO_2 is adopted from LiMn_2O_4 with the Li complete removal ,keeping the F-d3m Space Group same as LiMn_2O_4. The results have shown that the lattice length is increased due to the Li intercalation that affects the density of states(DOS) and band structure. It is clear that the electron transfer mainly occurs between Li and O other than between Li and Mn from the partial DOS integration Area. The nonrigid-band effect arises as a result of Li intercalation,. This is consistent with the K. Cho and J. Joannopoulous work. There is a predominant energy gap between the O-2p and Mn-3d, the e_g band shifts downward whereas its bonding counterpart e_g shifts up.