THE ELECTRONIC-SPECTRUM OF GALLIUM MONOIODIDE

The emission spectrum of the (GaI)-Ga-71 molecule, lying in the 3800-4 500 angstrom region and attributed to the A 3PI0-X 1SIGMA+ and B 3PI1- x 1SIGMA+ transitions has been reinvestigated. The spectrum of the sin gle isotopic species (GaI)-Ga-71 was excited using an electrodeless di scharge lamp run at 160-180 W microwave power (2450 MHz). More than 13 0 bands have been photographed on a 3.4 m Jarrell-Ash grating spectrog raph in second and third orders and assigned to the vibrational scheme s of the two systems. In both the systems reversal of shading has been observed in the bands of the same sequence and also secondary heads h ave been observed in several of the bands at high J. The A-X vibration al scheme has been extended to include bands involving upsilon'< 15 an d upsilon'' < 25. More precise vibrational constants have been determi ned which include the omega(e)y(e) term for the A 3PI0 state.