Semiclassical analysis correlation function

Comparisons of the correlation functions calculated quantum mechanically and semiclassically, like those presented in Fig. 6.2, show that the correction due to the dipole moment gradient included in (6.34) sometimes improves the accuracy especially for short propagation times. This correction affects not only the amplitude of the correlation function oscillation, but also its frequency and distortions due to the presence of high harmonics in the spectrum. An analysis of the spectrum of the correlation function indicates that including this correction in the formula enables additional quantum effects to be taken into account. 

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