The $X^{1}\Sigma ^{+}_{g}$X1Σg+ ground state of Mg2 studied by Fourier-transform spectroscopy

Abstract

The \documentclass[12pt]{minimal}\begin{document}${\rm A}^1\Sigma _{\mathrm{u}}^+$\end{document}A1Σu+ - \documentclass[12pt]{minimal}\begin{document}${\rm X}^1\Sigma _{\mathrm{g}}^+$\end{document}X1Σg+ UV spectrum of Mg2 has been investigated with high resolution Fourier-transform spectroscopy. Mg2 vapor was created in a heat pipe. Various spectroscopic methods have been employed, such as conventional absorption spectroscopy with light from a broad band lamp and laser-induced fluorescence. The high resolution of the Fourier-transform spectrometer, together with computer aided evaluation methods of the spectra, yields precise transition frequencies. The new data and data available from earlier investigations are applied in direct potential fits of lower and upper electronic states. Various representations of potential energy curves for the ground state \documentclass[12pt]{minimal}\begin{document}${\rm X}^1\Sigma _{\mathrm{g}}^+$\end{document}X1Σg+ have been employed and their benefits in terms of smallest number of parameters are discussed. Scattering lengths are derived for the homonuclear isotopologues and compared with previous results.