  The lowest doublet electronic state for the lithium trimer (2A') is
calculated for use in three-body scattering calculations using the valence
electron FCI method with atomic cores represented using an effective core
potential. It is shown that an accurate description of core-valence correlation
is necessary for accurate calculations of molecular bond lengths, frequencies
and dissociation energies. Interpolation between 2A' ab initio surface data
points in a sparse grid is done using the global interpolant moving least
squares method with a smooth radial data cutoff function included in the
fitting weights and bivariate polynomials as a basis set. The Jahn-Teller
splitting of the 2E' surface into the 2A1 and 2B2 states is investigated using
a combination of both CASSCF and FCI levels of theory. Additionally,
preliminary calculations of the 2A'' surface are also presented using second
order spin restricted open-shell Moller-Plesset perturbation theory.
