COMPREHENSIVE ANALYSIS OF THE A-X SPECTRUM OF I-2 - AN APPLICATION OFNEAR-DISSOCIATION THEORY

Hight resolution absorption spectra of the A (3) Pi(1u)-X (1) Sigma(g) (+) system of I-2, consisting of some 9552 lines of some 79 bands span ning the vibrational range upsilon' = 0-35 and upsilon '' = 3-17, have been recorded and analyzed. A fit to them which uses the previously d etermined accurate molecular constants for the X (1) Sigma(g)(+) state yields an accurate new set of molecular constants for the A state, in cluding the Lambda doubling constants. The A-state vibrational and ine rtial rotational constants, as well as mechanically consistent centrif ugal distortion constants, are represented by near-dissociation expans ions, yielding an accurate representation of the experimental data whi ch also provides a reliable global representation of all observed and unobserved vibration-rotation levels of this state. (C) 1996 American Institute of Physics.