  The He2-SF6 trimers, in their different He isotopic combinations, are studied
both in the framework of the correlated Jastrow approach and of the Correlated
Hyperspherical Harmonics expansion method. The energetics and structure of the
He-SF6 dimers are analyzed, and the existence of a characteristic rotational
band in the excitation spectrum is discussed, as well as the isotopic
differences. The binding energies and the spatial properties of the trimers, in
their ground and lowest lying excited states, obtained by the Jastrow ansatz
are in excellent agreement with the results of the converged CHH expansion. The
introduction of the He-He correlation makes all trimers bound by largely
suppressing the short range He-He repulsion.
  The structural properties of the trimers are qualitatively explained in terms
of the shape of the interactions, Pauli principle and masses of the
constituents.
