  Using the Multi-Reference Configuration Interaction method, the adiabatic
potential energy surfaces of Li3 are computed. The two lowest electronic states
are bound and exhibit a conical intersection. By fitting the calculated
potential energy surfaces to the cubic Exe Jahn-Teller model we extract the
effective Jahn-Teller parameters corresponding to Li3. These are used to set up
the transformation matrix which transforms from the adiabatic to a diabatic
representation. This diabatization method gives a Hamiltonian for Li3 which is
free from singular adiabatic couplings and should be accurate for large
internuclear distances, and it thereby allows for bound dynamics in the
vicinity of the conical intersection to be explored.
