MOLECULAR-DYNAMICS SIMULATIONS OF QUADRUPOLAR RELAXATION OF XE-131 INCARBON-TETRACHLORIDE, ACETONITRILE, AND METHANOL

The nuclear relaxation of Xe-131 in different solvents (carbon tetrach loride, acetonitrile and methanol) has been studied by means of molecu lar dynamics simulations. The solvation structure around xenon is exam ined with radial and angular distribution functions. Electric field gr adient time correlation functions (EFG-TCF) have been calculated for t he electric field gradient at the site of xenon, and are discussed in terms of molecular self- and cross-correlations. The amplitudes of tot al EFG-TCF for acetonitrile are comparable for the two potentials, a 3 -site and a 6-site model, although the self- and cross-correlation EFG -TCF differ significantly between the models. For all solvents, the si mulations give quadrupolar relaxation rates close to the experimental results.