Manganites with general formulas (formula presented) and (formula presented) where (formula presented) is a rare-earth ion, and (formula presented) is an alkaline-earth ion, are known as insulating pure or charge ordered compounds at low temperatures with some R and A. In the present work, it is shown how the charge ordering and crystal structure form the orbital structure, which strongly effects the superexchange interaction. An explicit space group and the magnitudes of the distortions of each crystal were used in the calculations. We assume an ideal insulating state of the crystals. The model presented in this work allows one to explain the (formula presented) and A magnetic structures in terms of charge and orbital structures using quantitative estimations of the exchange parameters. The model also allows one to find easy axis and noncollinear components of a multisublattice magnetic structure of manganites. © 2002 The American Physical Society.