A newly developed synthesis of X-ray data for crystal analysis, called the point diagram synthesis, is compared with the classical Fouriers. The fundamental assumption in the method s first explained. A correlation matrix of index 10 is then quoted. Some mathematical properties of the correlation matrices, that is, the absolute convergence, and the h- and μ-summation rules are described and illustrated. The method is next applied in parallel with the Fouriers to an arbitrary structure along with its two component structures. The crystal NaCl is next studied, using the actual experimental data. It is shown that on the basis of exactly the same experimental data the inormation given by the two types of syntheses are entirely different. Conclusions about the method drawn in the previous articles are then discussed in the light of the new studies and approved once more.