The Al,Si distribution in the framework of chabazites has been studied
as a function of the Al loading by Monte Carlo simulations. The atom
ordering has been characterized by several thermodynamic variables and
order parameters obtained from the simulations at room temperature. O
ne finds three different Al,Si ordering patterns, whose stability limi
ts are defined from characteristic changes in the thermodynamic variab
les. Long-range order is found in the atom distribution for Al loading
higher than 0.44. We have found similarities with the Al,Si distribut
ion in other zeolitic frameworks which include six-membered rings.