Electron contribution to energy of alkali metals in the scheme of an embedded atom model

The behavior of the energy of molecular dynamics models of alkali metals constructed using the embedded atom potential at high temperatures is discussed. Pair potentials and embedding potentials for lithium, sodium, potassium, rubidium, and cesium are presented as uniform analytical expressions. If the parameters of the potential of the embedded atom model (EAM) are selected based on the known dependence of the density of liquid metal on temperature, then, as temperature approaches the critical one, the actual energy increases faster than the energy of the models in all cases. The thermal contribution of electron gas to the energy of metal is considered as the cause of the discrepancy. It is shown that it is possible to eliminate the discrepancy between energies of models and the actual metal at high temperatures, if the energy of thermal excitation of electrons is taken into consideration. The difference between the actual energy of metal and the energies of EAM for liquid $\mathrm{Li}$, $\mathrm{K}$, and $\mathrm{Cs}$ is almost equal to the contribution of the thermal energy of electrons. The thermal energy of electrons is taken into account in analysis of data obtained using shock compression.