The distribution of charge states of all atoms in the unit cell ofRBa2Cu3Ox;x=6.7&hthinsp;(R=Yb,&hthinsp;Er,&hthinsp;Ho,&hthinsp;Y,&hthinsp;Gd,&hthinsp;Eu,&hthinsp;Sm,&hthinsp;Nd,&hthinsp;Pr)is determined on the basis of comparison of the theoretical calculated electric field gradient tensor and existing experimental data. The variation of the charge states of the atoms as a function of the ionic radius is analyzed. ©1999 American Institute of Physics.