Spin-polarized first-principles calculation of momentum densities of Fe

We perform first-principles calculations on the momentum densities in Fe. The ridge and valley appear on the ∑ and Δ lines, respectively, on the (001) plane. This anisotropic distribution of the momentum densities is found to originate from the difference between symmetries of the ∑( C _{2 v} ) and Δ( C _{4 v} ) lines. The calculated one-dimensional momentum densities of the majority spin have a broader distribution than those of the minority spin, which is expected to be due to the fact that the distribution in the real space of the majority spin is narrower than that of the minority spin. (paper)