Nonadditivity of interaction in Li(NH3)n and Li(NH3)n+ (n=1–4) clusters Original Research Article

Two- and three-body interactions are calculated by means of the B3LYP and MP4 methods to assess the nonadditivity of interactions in Li(NH3)n and Li(NH3)n+ (n=1–4) clusters. It is found that the three-body contributions to the total interaction energy are more important for Li(NH3)n clusters than for Li(NH3)n+ ones. For lithium ion–ammonia complexes correlation effects do not contribute significantly to the interaction energy. On the other hand, for the lithium atom–ammonia complexes the electron correlation seems to be rather important. The density functional approach is reliable to estimate the total interaction energies and nonadditive effects, especially for larger systems (n⩾4).