CORRELATIONS OF THE CU-63 NQR NMR DATA WITH THE CU-67(ZN-67) EMISSIONMOSSBAUER DATA FOR HTSC LATTICES AS A TOOL FOR THE DETERMINATION OF ATOMIC CHARGES/

A linear correlation between the quadrupole coupling constants C (Cu) measured by the Cu-63 NQR/NMR technique on the one hand and C (Zn) mea sured by the Cu-67/Zn-67 emission Mossbauer spectroscopy on the other hand has been found. The deviation from the linear dependence for a pa rticular substance indicates a considerable difference of the copper c harge state from 2+ or different orientations of the z-axes for the to tal and lattice electric field gradient (EFG) tensors on Cu-63. A simi lar deviation from the linear dependence of C (Cu) on the principal co mponent of the lattice EFG tensor calculated for the copper sites perm its to find a difference of the accepted model from the actual charge distribution in the HTSC lattice sites.