Multilayer relaxation of a clean bcc Fe{111} surface

A multilayer low-energy electron diffraction analysis of the Fe{111} surface structure has determined four interlayer spacings. This analysis is a refinement of an earlier analysis that used the same experimental data, but considered only variations of the first interlayer spacing. The first interlayer spacing shows a small increased contraction, but substantial changes are found in the deeper spacings. The optimized structure is (with dᵢₖ the spacing between ith and kth atomic layer) {Δ}d₁₂=(-16.9±{}3.0)%, {Δ}d₂₃=(-9.8±{}0.3)%, {Δ}d₃₄=(4.2±{}3.6)%, and {Δ}d₄₅=(-2.2±{}3.6)%, relative to the bulk spacing of 0.827 A{}.