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 $d_{\mathrm{ik}}$ the spacing between ith and kth atomic layer) Δ$d_{12}$=(-16.9±3.0)%, Δ$d_{23}$=(-9.8±0.3)%, Δ$d_{34}$=(4.2±3.6)%, and Δ$d_{45}$=(-2.2±3.6)%, relative to the bulk spacing of 0.827 Å.