Thermodynamic properties of the alkali metals at high temperatures and high pressures using mean-field potential model

We have carried out theoretical calculations for the thermodynamic properties of alkali metals at high temperatures and pressures. In the present study, we have used recently proposed mean-field potential (MFP) model of Wang and Li for evaluating the vibrational contribution to the total free energy. The recently proposed local pseudopotential of Filohais et al. is used to construct mean-field potential in terms of the total energy-volume relation. We have calculated static and shock compressions, bulk moduli (B-T and B-S), thermal expansion, specific heats (C-P and C-V), anharmonic contribution to the specific heat (C-V(ion-an)), enthalpy (E-H) and temperature along shock Hugoniot. We find that our computed results (except for C-P and C-V) are in good agreement with experiments as well as comparable with those generated by using first principles methods and other theoretical models. The present study indicates that in comparison with other theoretical models the present model is computationally simple, physically transparent and reliable to study the thermodynamic properties in the high pressures and high temperatures environment. (c) 2004 Published by Elsevier Ltd.