By using multireference single excitation configuration interaction calculations and multireference single and double excitation CI calculations, we consider the (1)Sigma(u)(+), (1)Pi(g), and (1)Pi(u) excited states of the F-2 molecule which lie between 4.3 and 14.1 eV above the ground state. The basis set is composed of 13s, 10p, 7d, and 2 f contracted Gaussian-type functions, and covers molecular orbitals spanned by 4s, 4p, and 3d Rydberg orbitals. Of the (1)Sigma(u)(+) states, G (1)Sigma(u)(+) is sometimes disregarded, presumably because it is not directly observed by optical measurements, but is inferred from perturbations in the visible and ultraviolet spectra. We find that G (1)Sigma(u)(+) arises from the shallow local minimum in the lowest (1)Sigma(u)(+) potential curve, which also has a stable minimum corresponding to the state designated C (1)Sigma(u)(+). The experimental excitation energies (T-0 values) for G (1)Sigma(u)(+) are 12.81-12.87 eV according to electron energy loss spectroscopy, and our theoretical value is 13.06 eV. Agreement between the experiment and the calculation is quite close. The state has a mixed ionic-Rydberg character with an interesting Rydberg portion. The experimental and calculated T-0 values for C (1)Sigma(u)(+) are, respectively, 11.57 and 11.59 eV, suggesting that the present calculation for the state is reliable. Ambiguity found in experimental assignments of the vibrational levels for C (1)Sigma(u)(+) is settled here. The (1)Pi(g) and (1)Pi(u) states are also discussed. (C) 2003 American Institute of Physics.