The Feynman path integral method is applied to the many-electron probl
em of quantum chemistry. We begin with investigating the partition fun
ction of the system in question; then, ''a classical path of electron'
' that corresponds to the Hartree-Fock approximation is obtained by mi
nimizing the thermodynamic potential of the system with respect to the
electron coordinate. The next-order approximation is obtained by eval
uating the deviation from this classical path, which is approximately
written by an easily integrable Gaussian integral. The result is expec
ted to be the random-phase approximation. As numerical examples, the h
ydrogen molecule and butadiene are treated. (C) 1994 John Wiley & Sons
, Inc.