Breit-Pauli energy levels and radiative lifetimes in neutral chlorine

Abstract

Breit-Pauli Energy levels, oscillator strengths and transition probabilities for all the transitions in Cl I between the fine structure levels of 3s2 3p5, 3s2 3p43d, 3s2 3p44s and 3s23p44p states are calculated using extensive configuration interaction (CI) wave functions. We have also determined the lifetimes of 3s2 3p43d, 3s2 3p44s and 3s2 3p44p levels. The relativistic effects are included through Breit-Pauli approximation via spin-orbit, Darwin and mass correction terms. Prior to the calculations of the oscillator strengths and transition probabilities, we fine-tune the CI coefficient using experimental energies. Our results are compared with experimental and other available theoretical data. The calculated energy levels are in close agreement with most of the NIST compiled data. We predict new lifetime data for several levels where no other theoretical and/or experimental results are available, which will form the basis for the future experimental work.