  First-principles calculation predict that olivine Li4MnFeCoNiP4O16 has
ferrotoroidic characteristic and ferrimagnetic configuration with magnetic
moment of 1.56 \muB per formula unit. The ferrotoroidicity of this material
makes it a potential candidate for magnetoelectric materials . Based on the
orbital-resolved density of states for the transtion-metal ions in
Li4MnFeCoNiP4O16, the spin configuration for Mn2+,Fe3+,Co2+, and Ni2+ is
t2g3eg2, t2g3eg2,t2g1t2g3eg1eg2, and t2g2t2g3eg1eg2, respectively. Density
functional theory plus U (DFT+U) shows a indirect band gap of 1.25 eV in this
predicted material, which is not simply related to the electronic conductivity
in terms of being used as cathode material in rechargeable Li-ion batteries.
