In many fields of science the key to the technological progress is the understanding and control of the materials properties at the atomic scale. In the same way, the origin of many properties of a material is related to the electronic structure. Consequently, the study of the properties of ferroic materials is naturally linked to the study of the electronic structure. On this basis, a big step to understanding the atomic arrangement and the properties of a material is analyzing the electronic structure and the different chemical bonds present in it. Experimentally, we can obtain the electron density maps from X-ray diffraction structural refinements. The electron density maps show the variation of electronic density along the unit cell. In this context, the application of the maximum entropy (MEM) method associated with the Rietveld allows a high precision to the atomic position determination and a better visualization of possible deformations caused by the sample doping. In the present study ceramic powders of (Bi1-xNdx)FeO3 (x = 0.025, 0.05, 0.075, 0.10, 0.15 and 0.20) compositions were obtained by high energy ball milling, followed by sintering in air atmosphere. By using of the X-ray Synchrotron radiation diffraction technique and the Rietveld structural refinement method it was concluded that there is a structural phase transition. For low x values the compositions have a rhombohedral symmetry with space group R3c and with the increase in neodymium substitution an orthorhombic symmetry with space group Pbnm takes place. The application Rietveld refinement associated with the maximum entropy method (MEM) allowed high precision in the structural phase’s and in the electronic structure’s determination.