  The time independent mean field method (TIMF) for scattering defines
biorthonormal sets of single-particle wave functions and corresponding creation
and annihilation operators. 2p - 2h correlations can be introduced through a
generalized random phase approximation; 1p - 1h contributions vanish (Brillouin
theorem). While the general variational method for scattering by Giraud and
Nagarajan solves inhomogeneous Euler equations by inversion of the standard,
hermitean Hamiltonian, the present approach diagonalizes a non-hermitean
Hamiltonian, which carries the information about entrance and exit channels.
