Determination of the structure of hydrogen on a W(211) surface

Abstract
Time-of-flight scattering and recoiling spectrometry is applied to structural analysis of hydrogen on a W(211) surface. Experimental data in the form of a recoiling structural contour map are presented and the hydrogen position is determined as 0.58±0.20 Å above the first-layer W plane and confined within a band that is centered above the [11¯ 1¯] troughs. Effective-medium-theory calculations predict a broad probability distribution for the H atom positions above the troughs due to thermally activated vibrational motion.