DISSOCIATION CHANNELS OF NAN+ CLUSTERS (3 LESS-THAN-OR-EQUAL-TO 37)

The dissociation of NaN+ clusters (N*37) has been studied using two cluster models and two different approximations to the exchange and correlation effects. First we show that the jellium model with the usual local-density approximation to exchange and correlation leads to dissociations mostly involving Na2 and Na8. This prediction does not agree with recent experimental results, which indicate that most NaN+ clusters dissociate emitting a neutral monomer. The explicit introduction of the ions eliminates many dissociations involving Na2 in favor of the channel involving a Na monomer. Furthermore, a nonlocal description of exchange and correlation lowers the stability of Na8 in favor, again, of dissociation through the monomer channel. In summary, the combined effect of these two improvements leads to a satisfactory description of the dissociation of NaN+ in comparison with experiment. © 1990 The American Physical Society.