Weak coupling theory for La2CuO4

Numerical calculations based on the weak coupling theory are carried out for La2CuO4. The main result is that there is a considerable difference between the Hubbard model with a single charge and the interaction of a general form with four effective charges. In the first case the metal is always unstable and, depending on the sign of the charge, it goes over either to the antiferromagnetic or superconducting state. In the general case the metal may remain stable or go over to the state, of a coherent mixture ''singlet superconductivity (SS)+spin density wave (SDW)+charge density wave (CDW)''. Paired coherent mixtures SS+CDW,SS+SDW and SDW+CDW should also be possible