The experimental ro-vibrational term values of the Na2 43Σg+ state both below and above the 3s + 3d atomic limit are analyzed. The multiparameter (double-well modified Lennard-Jones-DWMLJ) model function is proposed to fit a double-well potential. The earlier reported vibrational numbering of the predissociated terms (above 3s + 3d) is corrected and the final DWMLJ potential function for the Na2 43Σg+ state is reported. © 2005 Elsevier Inc. All rights reserved.