Figure shows a typical configuration from MD simulations highlighting the water molecules characteristic of the VSFG peak at 3400 cm -1 . This sub-population of water molecules is found in the first solvation shell of a CO 3 2-anion near the interface and displays a clear preferential alignment of their OH bonds, breaking inversion symmetry and making their vibrations visible in the VSFG spectrum. This prediction of unique water vibrations in the first solvation shell of CO 3 2is consistent with 2DIR studies in bulk water. The proximity to carbonate leads to a large electric field along the OH bonds, producing the observed red shift in the vibrational frequency relative to bulk water, while the charged interface leads to the observed alignment. In addition, the ion complex is shown in its most probable configuration near the cathode. The Na + cations are both in contact with the anion on opposite sides with the plane of CO 3 2-orthogonal to the interface. This snapshot should not be understood as an exclusive assignment of the peak, with every water molecule contributing to this spectral region being found in a nearly identical configuration. Instead, it represents the most common structure contributing to the emergent spectral peak, highlighting the conformational properties statistically associated with this spectral region. We note that within this configuration there exist multiple aligned water molecules between the ion pair complex and the surface, which may serve as a proton donor during the coupled proton/electron transfer required for CO 2 activation. However, future studies will be required to evaluate the effect of the observed interfacial water alignment on the CO 2 R reaction kinetics.