Atomistic simulation techniques based on the Born model of ionic solids have been used to investigate adsorption and ion exchange of Ba2+, Sr2+, Ca2+, Cd2+, Ni2+, Co2+, Cs+, K+, and Na+ in dehydrated zeolite A. This work has shown that relaxation of the framework greatly affects the position of the most stabile exchangeable cation sites. The results have considerable consequences for simulation studies showing that simulations are meaningful only if the framework is allowed to relax freely. The aluminum content in the zeolite framework was found to influence the size of the ring structures, which in addition influences the, exchangeable cation positions. The simulation results have identified stable adsorption sites for the exchangeable cations, which show good agreement with experimental crystallographic data. This indicates the viability of using atomistic simulation to probe the structure, stability, and diffusivity in zeolites.