Pure and alkali-ion-doped droplets of He-4

We present the results of variational Monte Carlo calculations of clusters of He-4 systems: We study the pure He-4 case and the case of a cluster doped with a single alkali-ion impurity. The results are compared with similar calculations in bulk He-4. Our trial wave function is a glue-shadow wave function that can describe successfully self-binding and localization in space. The local Bose-Einstein condensate in the pure clusters is calculated. We give the results on the microscopic structure of the doped cluster in terms of the radial density profile around the ion and of angular correlations. We have studied the case of Na+ and K+. In both cases the local order of the atoms in the first shell around the ion is quite distinct compared to that present in the bulk liquid. (C) 2001 American Institute of Physics.