Density- functional study of structural and electronic properties of Na_nLi and Li_nNa (1 <~ n <~12) clusters

Abstract

Equilibrium geometries and electronic-structure properties of Na_nLi and Li_nNa (n=1-12) clusters are obtained using ab initio molecular-dynamics method with the generalized gradient approximation for the exchange-correlation potential. The resulting geometries show that Li atoms become trapped inside the Na cage, while Na prefers to be on the periphery of Li clusters. The comparison of total binding energies indicates a high degree of stability for clusters with eight atoms. We also report polarizabilities for both series of Na_nLi and Li_nNa clusters. Polarizabilities are calculated by a finite field method. Our calculations demonstrate that Li impurity reduces polarizabilities of Na_n clusters while the doping of Na in Li_n clusters increases the polarizabilities.