Ordered distributions of Al atoms in frameworks of faujasite family are deduced for various Al contents. The proposed model explains observations that Y of a high crystallinity has the shape of a trigonal plate and that discontinuities appear in plots of Al contents vs lattice constants. For LaX and LaY, calculated populations of La on three kinds of sites are in good agreement with observed populations. It is predicted that Y containing 72 +/- 6 Al atoms per unit cell is chiral. The model is further extended to a region of much greater silica content.