Comparison between experimental (Sproviero et al. 2006d, red) and calculated (Haumann et al. 2005b, black) EXAFS spectra of OEC S-state intermediates of water splitting. Left: k-weighted EXAFS spectra. Right: Fourier-transformed spectra in r-space, showing three prominent peaks corresponding to scattering centers in the first (O,N), second (Mn in the core), and third (dangling Mn, Ca) coordination shells of Mn, respectively. Vertical dashed lines are included to facilitate the comparison of peaks for different S-states. Copyright 2006 American Chemical Society.