  The results of a previous work, where it was considered the effect of hole
doping on a simple model of the CuO2 planes in La2CuO4, are extended. The
parameters are adjusted with the objective to fix the known values of the gap
of 2 eV for this material and its dielectric constant of 21. We find again
indications of a "hidden" phase transition beneath the superconductor dome. The
transition is a second order one, and is associated with an energetic
coincidence of a ground insulator state (AFA)with an excited paramagnetic state
showing a pseudogap (PPG), at a critical point of the hole concentration around
xc=0.2. The evolution as a function of doping of the band structures and the
Fermi surface of the system in the phases AFA and PPG, is shown. In the zone of
low doping, the holes begin to occupy the states located at the mid of the
sides of the Brillouin zone, that in the AFA states have the strongest
antiferromagnetic character. Around the critical doping the results show that
in both phases, the Fermi surfaces and the energy spectrum of the filled
electronic states tend to coincide.
