Potential energy curves of diatomic molecular ions from high-resolution photoelectron spectroscopy. III. The low-lying ungerade states of Kr2 +

Spectra of the v + = 55 − 74 vibrational levels of the I(1/2u) ground electronic state and the v + = 0 − 9 levels of the II(1/2u) excited electronic state of and 84Kr–86Kr+ have been measured by pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy. The spectra were recorded following (2+1′ ) resonance-enhanced multiphoton excitation via several vibrational levels of the Rydberg state of Kr2 located below the Kr(1 S 0) + Kr*(4p55p[1/2](J = 0)) dissociation limit. A combination of these results with earlier measurements of the vibrational level structure of the I(1/2u), I(3/2u) and II(1/2u) states of was used to determine two sets of analytical potential energy curves for the first three electronic states of ungerade (u) symmetry of . The first set of curves was obtained without explicit consideration of the spin–orbit interaction by adjusting the potential parameters of three independent curves to fit the experimental data. The second set of curves was determined using a global potential ...