K clusters incorporated into zeolite K-LTA causes ferromagnetism below 8 K. Distribution of K+ ions in its alpha-cages was studied by X-ray powder diffraction. On the basis of space group F23, electron-density distribution was determined by Rietveld analysis followed by iteration of analysis by a maximum-entropy method and whole-pattern fitting. K+ ions were located in alpha-cages in such a way that K clusters between adjacent alpha-cages are not equivalent to each other, which will lead to the ferromagnetism with antiferromagnetic components.