Global analysis of step-scan FTIR data of LHCII excited at 475 nm showing the lutein-Chl shared triplet state. (A) The DADS have a 20 μs component (black line, DADS1), with an amplitude of 90% (lutein-Chl shared triplet) and a nondecaying component (blue line, DADS2) that has an amplitude of 10% (unquenched Chls). For clarity, the spectra have been normalized to the keto modes. (B and C) For comparison, the FTIR of the lutein (B) and Chl a (C) triplet (redrawn from Bonetti et al. (26)) in THF are also plotted.