Rovibrational structure and potential energy function of the X0+ ground electronic state of ArXe

Rotationally resolved (1 + 1′) resonance-enhanced two-photon ionization spectra of the D0+,C1←X0+ band systems of several isotopomers of ArXe were recorded at high resolution in the wave-number range from 77000cm-1 to 77300cm-1 using a near-Fourier-transform-limited vacuum-ultraviolet laser system. The rotational structure of the v″=0,1 vibrational levels of the X0+ ground state of ArXe could be fully resolved and assigned, leading to a new set of spectroscopic parameters. A 'direct potential fit' to a combination of these data with microwave spectroscopy results [W. Jäger et al., J. Chem. Phys. 99 (1993) 919-927] and virial coefficients yields an accurate new potential energy function with equilibrium distance Re=4.095773(29)Å and well depth De=129.81(38)cm-1.