Temperature Dependence of Entropies and Specific Heats of Liquid Na and K

The temperature dependence is investigated of the entropies and specific heats of liquid Na and K. The systems are primarily modelled with a hard sphere (hs) description, but contributions arising from the soft forces and electronic part are also included with the basic hs model. The hard sphere ingredients at various temperatures are determined through the consideration that the difference between the relevant pair potential and its minimum value is just equal to the kinetic energy of a free particle. The basic ingredients thus obtained are employed to calculate the entropies and specific heats of the systems at various temperatures. The calculated values are found to be in good agreement with experiments.