A Full-Con¯guration-Interaction Nuclear Orbital treatment has been recently developed as a bench-
mark Quantum-Chemistry-like method to study small doped 3He clusters [J. Chem. Phys. 125,
221101 (2006)]. Our objective in this paper is to extend our previous study on (3He)N-Cl2(B)
clusters, using an enhanced implementation that allows employing very large one-particle basis
sets [J. Chem. Phys. 131, 174110 (2009)], and apply the method to the (3He)N-Cl2(X) case,
using both a semi-empirical T-shaped and an ab initio He-dopant potential with minima at both
T-shaped and linear conformations. Calculations of the ground and low-lying excited solvent states
stress the key role played by the anisotropy of the He-dopant interaction in determining the global
energies and the structuring of the 3He atoms around the dopant. Whereas 3He atoms are local-
ized in a broad belt around the molecular axis in ground-state N-sized complexes with N=1¡3,
irrespective of using the T-shaped or the ab initio He-dopant potential function, the dopant species
becomes fully coated by just four 3He atoms when the He-dopant potential also has a minimum
at linear con¯gurations. However, excited solvent states with a central ring-type clustering of the
host molecule are found to be very close in energy with the ground state by using the ab initio
potential function. A microscopic analysis of this behavior is provided. Additional simulations of
the molecular ro-vibrational Raman spectra, also including excited solvent states, provide further
insights into the importance of proper modeling the anisotropy of the He-dopant interaction in
these weakly bound systems and of taking into account the low-lying excitations.
Keywords: doped helium clusters, full-con¯guration-interaction, quantum-chemistry-like, hard-core interac-
tion, ro-vibrational Raman spectroscopyPeer reviewe
