Inhomogeneous electron density in the static field of nuclei

We consider the thermodynamic potential of a Coulomb system of electrons and nuclei in the adiabatic approximation for the nuclei subsystem. In this approximation, the indirect interaction of nuclei is completely determined by the inhomogeneous density of the electron subsystem in the static field of nuclei. We obtain a decomposition of the inhomogeneous electron density as a sum of “one-center,” “two-center,” etc., group functions of electrons. Based on this, we consider the atomic partition function and the quasineutrality condition in a dilute atomic plasma.