Abstract
The chemical shift of 129Xe adsorbed on a zeolite as a probe is given by the sum of terms characteristic of the factors to which the gas may be submitted : collisions with other xenon atoms and with the surfaces of cages or channels, electrical charges of the cations and of the lattice. While it does not provide an absolute value of the local electric field in a zeolite this technique makes it easy to locate the cations and to determine their relative electric effects.