The E-1 Sigma(+)(g) state of lithium dimer revised

This article describes the use of the inverted perturbation approach method for construction of an accurate potential energy curve of the E(1)Sigma ()(g) "shelf" state in Li-2. Contrary to previous reports the applied method provides a potential curve free of unphysical oscillations and reproduces energies of all the levels known from previous experiments. Our results con firm the possibility of describing the E state within the Born-Oppenheimer approximation. (C) 2001 American Institute of Physics.