Abstract
The structures and relative stabilities of the Ca2+Xen (n = 1-18) clusters have been carried out using two methods: the pairwise/Monte Carlo Basin-Hopping and density functional theory methods. The lowest energy structures have been determined using classical energy minimization method where the total interactions have been obtained as a sum of pairwise potentials. The DFT calculations have been performed using the dispersioncorrected functional B97D3. For both methods the stable structures are characterized by the Ca2+ being coated by a shell of xenon atoms. For the smallest sizes n < 4, we show that the many-body contributions in the DFT calculations stabilize the linear or planar structures while the two-body contributions in the pairwise calculations yield three-dimensional structures. For larger sizes, capped square antiprism (CSA) packing is dominantly found and the first solvation shell is saturated at n = 10. The stability analyses have shown magic numbers which are consistent with the CSA growth sequence.