The problem of multiple solution is frequently a result of Patterson analysis. This problem can be solved by making use of the component relations or the phase relations of the multiple-solution type. A pseudo structure model containing simultaneously the actual structure and its symmetrical equivalents is in turn the basis for the application of the component relations or the phase relations of the multiple-solution type. The so-called Multiple-solution Fourier Syntheses is the Fourier syntheses based on the whole or partial pseudo structure model. This model can be developed and improved by this type of Fourier syntheses. A practical example is given.