Electronic structure with rovibrational and dipole moment calculation of the diatomic molecules AsBr and AsI

Abstract

CASSCF/MRCI calculations have been performed for the ground and the low-lying singlet and triplet excited electronic states, in the representation 2s+1Λ(+/−) of the diatomic molecules AsBr and AsI. Twenty and seventeen excited electronic states have been investigated respectively for AsBr AsI molecules. The potential energy curves, the electronic energy with respect to the ground state Te, the harmonic frequency ωe, the internuclear distance Re, the rotational constant Be, and the static and transition dipole moment have been investigated for the considered electronic states. The comparison between these constants of the four As-halides has been done along with the energy levels Te for the different electronic states. By using the canonical functions approach, the eigenvalue Ev, the rotational constant Bv, and the abscissas of the turning points Rmin and Rmax have been calculated for the considered electronic states up to the vibrational level v=100. The comparison between the values of the present work with the experimental data available in the literature shows a very good agreement. This study represents the first theoretical investigation of the electronic structure of both AsBr and AsI molecules.