The Cl(2p) photoelectron spectra of the HCl and DCl molecules: the effects of the molecular field

The Cl(2p) photoelectron spectra of HCl and DCl have been measured with high resolution. Careful data analysis with a least-squares fitting method enabled us to determine the spectroscopic parameters for the three spin-orbit and molecular field split components of the Cl(2p)-1 states. The experimental results were compared with ab initio calculations. The values of 84±9 meV, 71±13 meV, and 103±10 meV for the lifetime line widths of 2 Pi 1/2 , 2 Sigma 1/2 + , and 2 Pi 3/2 states were extracted from the experiment. An anomalous photoionization cross section ratio (60%) between the 2 Sigma 1/2 + and 2 Pi 3/2 states was observed.