Nanocrystalline powders of cerium doped gadolinium gallium garnet (Gd3Ga5O12, GGG) powders were prepared by an aqueous sol–gel method. Effects of Ce doping on the microstructure, band gap energy and electron density distributions of the grown Gd3−xCexGa5O12 (x = 0.5, 1 and 3) have been studied by means of scanning electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction techniques and the maximum entropy method (MEM). The mid bond densities between different atoms of Gd3−xCexGa5O12 (x = 0.5, 1 and 3) obtained from 1D electron density profiles are analyzed.