15min:

N. NISHIMIYA AND T. YUKIYA, Department of System Electronics and Information Technology, Department of Applied Computer Science, Tokyo Plolytechnic University, Iiyama 1583, Atsugi City, 243-0297 Kanagawa, JAPAN.

The doppler limited electronic vib--rotational absorption spectrum of A³ ₁ X^{1 +} system in I^35/37Cl is measured in the 11300 -- 13200 cm^-1 region using a Ti:Sapphire Ring Laser (Coherent 899-21). The 56 bands belonging to (v' = 0 7) (v'' = 0 6) in I^35/37Cl are assigned. The

Dunham coefficients of the X^{1 +} state are calculated based on a global

reduced least squares fitting procedure. The Y''₁₀ and Y''₀₁ reported by Hedderich et al. are

taken into

the calculation because we

do not have sufficient spectrum belonging to v''= 0 2. In the A³ ₁ state, the T'_v, B'_ve/f, D'_v and H'_v are

determined instead of the

Dunham coefficients to avoid the distortion of the potential.

%A multiple precision arithmetic library was used in this procedure

To investigate the accuracy of

Dunham coefficients determined

in the X^{1 +} state, the absorption lines of 4' 0'' and 5' 0'' bands are assigned in the 14438 -- 14491 cm^-1 region where measurements are performed intermittently. Those lines are well positioned within the limit of the standard deviation.