GROUND AND EXCITED-STATES PROPERTIES OF NA4FM=1-3, LI4H AND LI4H2 CLUSTERS

Stable ground state structures for neutral and charged Li(n)H, LinH2 a nd Na(n)F(m) (n not-equal m) have been determined using ab - initio me thods accounting for electronic correlation effects. The consequences of replacing alkali-atom by foreign-atom or -atoms have been studied. The similarities and differences with respect to topologies of the mos t stable Li(n) and Na(n) clusters will be pointed out. The ionization potentials and spectroscopic patterns are compared with available expe rimental data. This allows for the geometrical and spectroscopic assig nments as well as for a study of the influence of localized versus non localized bonding on the ground and excited state properties of mixed clusters.