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) d12=(-16.93.0)%, d23=(-9.80.3)%, d34=(4.23.6)%, and d45=(-2.23.6)%, relative to the bulk spacing of 0.827 AIS.