Deperturbation of the rotational spectrum of the d 3Δ–a 3П (7,1) band of CS radical

Abstract: The spectra of d 3Δ–a 3П (7,1) band of CS radical were measured by optical heterodyne–concentration modulation spectroscopy in the region from 11640 to 12230cm−1. In total, we assigned three hundred and four lines, of which Ree and Rff branches in the d 3Δ1–a 3П0 subsystem and more than a hundred lines were first observed and identified. The anomalous lambda-doubling of the d 3Δ1 (υ =7) level reveals a local perturbation interaction from the 1Σ− state. The perturbation parameter between 1Σ− and a 3П0 (υ =13), and molecular constants of the d 3Δ1 (υ =7) as well as 1Σ− were derived through fitting all assigned lines to the effective Hamiltonian. [Copyright &y& Elsevier]