Theoretical study of the absorption spectra of the sodium dimer

Absorption of radiation from sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X (1)Sigma (+)(g),+ state to the first excited A (1)Sigma (+)(u) and B (1)Pi (u) states and from the triplet a (3)Sigma (+)(u) state to the first excited b (3)Sigma (+)(g) and c (3)Pi (g) states are studied quantum-mechanically. Theoretical and experimental data are used to characterize the molecular properties, taking advantage of knowledge recently obtained from nb initio calculations, spectroscopy, and ultracold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 1000 to 3000 K, and are compared with previous calculations and measurements where available.