Gaussian shaped PIPs

Fig. 2. A Gaussian shaped PIP with a phase increment A

Fig. 6. Computer simulated excitation bands (n = — 2 to 2) by a Gaussian shaped PIP (Table 2), where the centre band (w = 0) is shifted to 10 kHz and the spectral width of each band is 4 kHz. The amplitudes of the profiles are asymmetric in response to the asymmetric effective RF fields.

Table 3. The frequencies / , phases 9n of the effective RF fields and the amplitudes A of the excitation bands created by a Gaussian shaped PIP with the same parameters as that in Table 2, except for a A0 = O.82jt and 27rA/r = (2m + 0.5)jr...

As the hot band transitions should exist in both of the v, band of hydrogen-bonded and physisorbed acetonitrile, we must get the accurate v, band without the effect by the hot band transitions. We have to determine the analytical functions for fundamental transitions of v/a and vJp and for hot band transitions upon the least-squares procedure. We assumed that the reorientational-vibrational relaxation processes of physisorbed acetonitrile could be described as a diffusion process like bulk liquid molecule, whose spectral density has a Lorentzian form. Accordingly it is supposed that the v,p band is reproduced as a sum of three Lorentzian curves of the v, p, v," p, and bands. In the previous study [9], it was assumed that the Vj a band has a Gaussian band shape and the hot band transitions could be ignored. In the present study we assumed that the v,a band over the range of PIP, =... 

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