Exact diagonalization of many-Fermion Hamiltonian combined with wave-function readjustment:: Application to one-dimensional systems

We describe briefly a new method of approach to the interacting fermion and boson systems. Namely, we determine the explicit form of the single-particle wave functions {w(i)(r)} appearing in the microscopic parameters of models in the second-quantization representation. The method is illustrated on the examples of H(2) molecule and He atom, the Hubbard chain, and a ring of N less than or equal to 10 atoms.