The KRb (2)3Σ+ electronic state

High-resolution spectra of the (3)(1)Pi --> (2)(3)Sigma(+) system of the KRb molecule, obtained after excitation with fixed frequencies Ar+ laser lines, were recorded on a Connes-type Fourier transform interferometer. Molecular constants of the first 14 vibrational levels of the (2)(3)Sigma(+) state an determined. The RKR potential energy curve is derived. The main spectroscopic constants for this triplet electronic state of the K-39 Rb-85 isotopic species are T-e = 13 507.146(2) cm(-1), omega(e) = 48.6385(6) cm(-1), B-e = 0.0254152(5) cm(-1), gamma = 0.00164(4) cm(-1), epsilon = -0.469(2) cm(-1), R-e = 4.98345 Angstrom, D-e = 3447 cm(-1) (C) 2000 Academic Press.