Computation of collective modes and acoustic investigations at different temperatures of vitrous silica

This paper is mainly concerned with elastic and acoustic properties of vitrous silica besides the computation of phonon frequencies. Thus the phonon frequencies of vitrous silica have been calculated assuming the electronic bulk modulus, Ke, as equal to zero. New equations have been derived to relate the pressure derivatives of second order elastic constants to the acoustic Gruneisen's parameters using both Bhatia-Singh's parameters and Schofield's equations. The calculated longitudinal and transverse Gruneisen's parameters and the predicted absorption band spectra from Nagendranath's equation and Bhatia Singh's parameters are in good agreement with experiment. The calculated mean acoustic mode Gruneisen's parameter evaluated from the pressure derivative of Nagendranath's equation is also in good agreement with experiment

Structure and allied properties of liquid carbondisulphide

Orientational model for liquid CS2 has been reviewed and shown that proper selection of centre structure produces molecular structure factors comparable with reference interaction site model (RISM) for both x-ray and neutron data even with the parallel alignment suggested by Suzuki and Egelstaff. With this justification of orientational model next centre structure factors were calculated from measured structure data and therefrom obtained various correlation functions including the pair potential and partial structures