Undercooled state of liquid rubidium

A first principle theoretical scheme which is based on pseudopotential perturbation theory, the thermodynamics of hard sphere systems and the variational method based on Gibbs-Bogoliaubov inequality is used to investigate the specific heat of liquid Rb in the undercooled region (T< T_m). C^l_p is found to increase with decreasing T and exhibits a maxima in the vicinity of 60 K. The anomalies in C^l_p in the undercooled region are discussed in terms of structure and volume dependent contributions of energies and entropies.