Density-functional theory of potassium atoms in zeolite

We have constructed a model of a zeolite which we have optimized using dens ity-functional theory (DFT) in local-density approximation. We have calcula ted the energy of the zeolite model with and without one potassium atom. Fr om these calculations the adsorption energy of the K atom is found to be - 1.057 eV. We find that the bonds in the zeolite ring show an expansion upon addition of a K atom. We have also calculated the spin-dependent bond ener gy for two K atoms in a zeolite, from which we predict that ferromagnetic o rder occurs. (C) 2000 Elsevier Science B.V. All rights reserved.