Capone, MatteoNarzi, DanieleTychengulova, AliyaGuidoni, Leonardo2019-06-182019-06-182019-06-182019-05-0110.1111/ppl.12949https://infoscience.epfl.ch/handle/20.500.14299/157388WOS:000466108300005Understanding the structural modification experienced by the Mn4CaO5 oxygen-evolving complex of photosystem II along the Kok-Joliot's cycle has been a challenge for both theory and experiments since many decades. In particular, differential infrared spectroscopy was extensively used to probe the surroundings of the reaction center, to catch spectral changes between different S-states along the catalytic cycle. Because of the complexity of the signals, only a limited quantity of identified peaks have been assigned so far, also because of the difficulty of a direct comparison with theoretical calculations. In the present work, we critically reconsider the comparison between differential vibrational spectroscopy and theoretical calculations performed on the structural models of the photosystem II active site and an inorganic structural mimic. Several factors are currently limiting the reliability of a quantitative comparison, such as intrinsic errors associated to theoretical methods, and most of all, the uncertainty attributed to the lack of knowledge about the localization of the underlying structural changes. Critical points in this comparison are extensively discussed. Comparing several computational data of differential S-2/S-1 infrared spectroscopy, we have identified weak and strong points in their interpretation when compared with experimental spectra.Plant Sciencesoxygen-evolving complexwater-oxidizing complexquantum mechanics/molecular mechanicsd1 polypeptides-2 stateundergoes oxidationstructural-changesmn4cao5 clusterno evidencemn-clustertext::journal::journal article::research article