ON THE sp2 CONFIGURATIONS AND CONFIGURATION-MIXING IN THE FIRST SPECTRA OF INDIUM (In I) AND THALLIUM (Tl I)

Several aspects of configuration-mixing effects in the spectra of In I and Tl I are discussed, and evidence supporting an earlier conclusion that sp22D in In I lies above the first ionization potential is given. Experiments on the absorption spectra of shock-heated In and Tl vapors have revealed the weak In I [Formula: see text] transition and a new Tl I doublet [Formula: see text]. The profile of the Tl I [Formula: see text] autoionization feature has been obtained by experiments with a furnace and scanning monochromator, and the result is compared with the theory of Beutler–Fano resonances.