Phonon dispersion in polyguanylic acid

A study of the normal modes of vibration and their dispersion in polyguanylic acid along the chain axis (tetrad form) based on Urey–Bradley force field and Raman and Fourier transform infrared is reported. It has been greatly assisted by the vibrational analysis of guanine tetrad and spectral information for telomeric DNA d(G12). Spectral relationship for polyG, telomeric DNA d(G12) and characteristic features of dispersion curves such as regions of high density-of-states, repulsion and character mixing are discussed. Predictive value of heat capacity as a function of temperature is reported.