Distributed multipole analysis on the basis of periodic Hartree-Fock (PHF)-type calculations, using the CRYSTAL95 code is applied to 12 aluminophosphate molecular sieves. Several approximations of the dependence of the Mulliken atomic charges and dipole moments of the crystallographically independent oxygen atoms calculated with the STO-3G, ps-21G*. and 6-21G* basis sets are obtained with respect to three oxygen parameters (i.e, average value and difference between the Al-O and P-O bond distances, and Al-O-P angle). Some deflections from these approximate forms for the different oxygen types are discussed.