title: On the electron-electron counterbalance hole.
abstract: When a many-electron system has spatial inversion symmetry, the electron-electron counterbalance hole implies that two electrons with parallel spins cannot be at opposite positions with respect to the inversion center, and its presence was pointed out in the literature [T. Koga, J. Chem. Phys. 108, 2515 (1998)] for any pairs of Hartree-Fock orbitals with the same inversion parity. We report here a generalized result that in all two-electron systems with spatial inversion symmetry, the electron-electron counterbalance hole always exists for any approximate and exact wave functions with even inversion parity. The same is also true in momentum space. An extension of the hole to systems with three or more electrons is discussed.
authors.affiliation: Department of Applied Chemistry, Muroran Institute of Technology, Muroran, Hokkaido 050-8585, Japan. koga@mmm.muroran-it.ac.jp
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Koga
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sekiya