The KRb ground electronic state potential up to 10 Å

High resolution spectra of the A 1Σ+→X 1Σ+ system of the KRb molecule, obtained after excitation using a titanium-doped sapphire laser, were recorded on a Connes-type Fourier transform interferometer. Molecular constants of the first 88 vibrational levels of the X 1Σ+ state are determined, and the potential energy curve is derived up to an internuclear distance of 10.419 Å (99.3% of the potential well depth). The energy of the dissociation limit is found as De=4217.3 (15) cm−1 (referred to the bottom of the potential curve well), in good agreement with the theoretical predictions of Jenč and Brandt [J. Mol. Spectrosc. 154, 226 (1992)] who gave De=4220 (20) cm−1 and the value De=4217.4 (8) cm−1 reported by Kasahara et al. [J. Chem. Phys. 111, 8857 (1999)].