Computer simulation of the structure of the hydration shells of calcium and calcium-water-zeolite a

A potential function is suggested to describe the interaction of the calcium ion with the water molecule using the tetrahedral model of the water molecule. Monte Carlo simulations of small clusters Ca(H2O)n (n≤20) and analyses of the resulting F-structures showed that the coordination number of Ca is 8. The structure of water adsorbed in the α-cavity of zeolite CaA depends predominantly on interactions with Ca2+ ions. The water molecule forms one hydrogen bond with an oxygen atom of the framework; the molecules are not hydrogen-bonded with each other. In this respect the structure of water in the Ca form of zeolite A resembles that in the Na form but differs from that in the K form.