A quantum chemistry approach to energies, structures, and spectroscopy of doped helium clusters

Abstract

Diffusion and path integral Monte Carlo methods are currently, and successfully, used to describe structures and binding energies of helium clusters doped with some impurity. For diatomic dopants, by considering the He atoms as "electrons" and the dopant as "nuclei" within a Hartree/Hartree-Fock framework, our group has developed a complementary tool which, in addition to the above mentioned properties, provides us with wave-functions. It allows to perform spectral simulations that can be compared with the experiment. This paper reviews the fundamental aspects of such quantumchemistry-like methodology in which, together with masses, Coulomb interactions are replaced by proper molecular ones. Extensions towards more accurate ab initio methodologies are outlined. Finally, the challenging scenario arising when the impurity is not immersed but attached to the nanodroplet, giving rise to an unusual "solar" system in which the planets no longer move around the dopant as a "sun", is addressed. © 2012 American Institute of Physics.