Spectroscopic investigation of the double-minimum 2 1Σu+ state of the potassium dimer -: art. no. 042509

The double-minimum 2 (1)Sigma(u)(+) state was investigated in K-39(2) and (KK)-K-39-K-41 molecules by analyzing spectra of the 2 (1)Sigma(u)(+)<--X(1)Sigma(g)(+) band system, simplified by polarization labeling. A wide range of rovibrational levels 21 less than or equal to v less than or equal to 97, 18 less than or equal to J less than or equal to 159 was observed. By using the inverted perturbation approach to construct the exotic potential-energy curve, an accurate, isotopically consistent description of the 2 (1)Sigma(u)(+) state has been obtained.