  In electrochemistry, reactions and charge-transfer are to a large extent
determined by the atomistic structure of the solid-liquid interface. Yet due to
the presence of the liquid electrolyte, many surface-science methods cannot be
applied here. Hence, the exact microscopic structure that is present under
operating conditions often remains unknown. Reflection anisotropy spectroscopy
(RAS) is one of the few techniques that allow for an in operando investigation
of the structure of solid-liquid interfaces. However, an interpretation of RAS
data on the atomistic scale can only be obtained by comparison to computational
spectroscopy. While the number of computational RAS studies related to
electrochemical systems is currently still limited, those studies so far have
not taken into account the dynamic nature of the solid-liquid interface. In
this work, we investigate the temporal evolution of the spectroscopic response
of the Au(110) missing row reconstruction in contact with water by combining ab
initio molecular dynamics with computational spectroscopy. Our results show
significant changes in the time evolution of the RA spectra, in particular
providing an explanation for the typically observed differences in intensity
when comparing theory and experiment. Moreover, these findings point to the
importance of structural surface/interface variability while at the same time
emphasising the potential of RAS for probing these dynamic interfaces.
