Hiroyuki KAWABE (Kinjo College), Hidemi NAGAO and Kiyoshi NISHIKAWA (Kanazawa Univ.)
[Intern. J. Quantum Chem. 59, 457 (1996)]
The Feynman path integral method is applied to the many electron problem of quantum chemistry. We begin with constructing new closure relations in terms of the LCAO coefficients, and investigate the transition amplitude and the partition function of the system in question, then "a classical path of electron" which is described by the time dependent Hartree-Fock-Roothaan equation is obtained by minimizing the action integral of the system with respect to "the electron coordinate." The next order approximation is obtained by evaluating the deviation from the classical path, which is approximately written by a Gaussian integral. The result is expected to be the random phase approximation.