ROTATIONAL AND HYPERFINE ANALYSIS OF THE (0,0) BAND OF THE B-2-SIGMA(-X(2)SIGMA(+) SYSTEM OF INDIUM MONOXIDE())

The InO molecule has been produced in a molecular beam using a laser v aporization source, and its (0,0) band, near 428.2 nm, has been studie d by laser-induced fluorescence at sub-Doppler (similar to 0.005 cm(-1 )) resolution. The spectrum is characterized by impressive nuclear mag netic hyperfine structure due to the In-115 nucleus. Analysis of the r otational and hyperfine structure in the band indicates that the trans ition is B-2 Sigma(+) (case b(beta S))-X(2) Sigma(+) (case b(beta J)) in which there is a large hyperfine splitting in the upper state and a predominantly spin-rotation splitting in the lower (ground) state of the molecule. The band origin, v(0,0), lies at 23 332.296 cm(-1), and derived constants, in cm(-1), for the two v = 0 levels are as follows: [GRAPHICS] Dispersed fluorescence experiments and photographic emissi on spectroscopy using microwave excitation, hollow cathode and de are sources have been employed to obtain vibrational data.