Theory of Vibrational Overtones and Rotational Excitations in Solid Parahydrogen –Frequency Analysis of the Infrared Spectra–

Infrared absorption spectra of S v (0), Q v (0)+ S 0 (0) and S v (0)+ S 0 (0) ( v =1, 2,…) in solid parahydrogen are calculated on the basis of the induction mechanism of dipole moment. Effects of the propagation of rotational excitation on the spectral shape through the electric quadrupole-quadrupole interaction are studied in detail, in agreement with the recent experiments. The difference of the excitation energy in the solid phase from that in a free molecule, which increases systematically for higher overtones, is discussed. The dispersion and overlap interactions can be shown to cause such difference.