  We have analyzed the quasiparticle dispersion and ARPES-spectral density for
Sr2CuO2Cl2 and Ca2CuO2Cl2 antiferromagnetic insulators along basic symmetric
directions of the Brillouin zone (BZ) in a framework of an extended tight
binding method (ETBM) with explicit account for intracell strong electron
correlations. The quasiparticle dispersion is in a good agreement with ARPES-
data. At the top of valence band we found a narrow impurity-like virtual level
with the spectral weight proportional to the concentration of spin
fluctuations. A pseudogap between the virtual level and the top of the valence
band has dispersion similar to 'remnant Fermi surface' in Ca2CuO2Cl2 and to a
pseudogap in the underdoped Bi2212 samples. A calculated parity of the
polarized ARPES-spectra in (0,0),(pi/2,pi/2),(pi,0) - points in the AFM- phase
is even with regard to relative magnitudes of the partial contributions by
different orbitals to the total ARPES- spectral density. Conditions of an
observability for the different partial contributions in the polarized ARPES-
experiments are determined also.
