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A recently proposed technique based on the Fourier transform of the spectrum is applied to the stimulated-emission pumping spectrum of acetylene at -26 500 cm -1 above the vibrational ground state. Correlations on two different time scales ( -3 and -45 ps) were found from analysis of lowresolution (0.3 cm -1 ) and high-resolution (0.05 cm -1 ) spectra, respectively. Additional structure produced dynamic information on a wider (0.5-300 ps) time scale. The results show that acetylene at 26 500 cm " l is in the transition from the regular to the chaotic regime.

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