Interatomic potentials and the van der Waals' coefficient for the intercombination Cd 326.1 nm absorption line broadened by cadmium pressure

The intercombination absorption line of Cd 326.1 nm broadened by cadmium pressure is analysed in the spectral range 300-350 nm. The temperature dependence of the profile is studied and interpreted in the framework of the quasi-static theory. The difference of the van der Waals' coefficients Delta C-6 between the upper and lower states is found to be equal to 168 +/- 2 eV Angstrom(6). The interaction potentials of the ground (X(1)0(g)(+)) and the excited ((3)0(u)(+)) states are determined from 2.6 to 4.6 Angstrom and that of the other excited state ((3)1(u)) from 3.6 to 7.1 Angstrom. The well depths of the first two of these states are in close agreement with those obtained from other experimental methods. The well depth for the excited (3)1(u) state was found to be much greater than 1400 cm(-1). It was also found that the ground state potentials obtained independently by C. Bousquet (J. Phys. B, 19 (1986) 3859) and Su Ching-Hua et al. (J. Chem. Phys. 81 (1984) 9) coincide perfectly if the Bousquet potential is shifted by 1.52 Angstrom towards higher internuclear separations.