On the method of collective variables in the statistical theory of fermi systems of charged particles

A representation is obtained for the partition function in the form of a differential operator acting in the space of collective variables $\rho_{km}$ on an exponential with potential energy expressed in these variables. A quantum generalization of the virial expansion is constructed on the basis of this representation. The second virial coefficient is calculated for a nondegenerate gaslike plasma to $e^6$. Degeneracy effects in plasmas are considered near the classical limit $(\lambda/\beta e^2\ll1)$. An expression is found for the electron part of the energy of a metal in the form of a series in the electron-ion interaction.