Theoretical study of the absorption spectra of the lithium dimer

Abstract

For the lithium dimer we calculate cross sections for absorption of radiation from the vibrational-rotational levels of the ground $X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ electronic state to the vibrational levels and continua of the excited $A{}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ and $B{}^{1}{\ensuremath{\Pi}}_{u}$ electronic states. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from photoassociation spectroscopy and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 1000 to 2000 K and are compared with previous calculations and measurements where available.