Relativistic Multichannel Theory: Theoretical Studies of Excited Energy Structure of Ar Atom

We here present a relativistic multichannel theory which can be regarded as an extension of traditional configuration interaction theories by including continuum configuration interactions. Our relativistic multichannel theory aims directly to calculate the compact set of physical parameters ( μ_α,U_iα ) in multichannel quantum defect theory. Taking Ar atom as an example, we compare our calculated orbital energies with traditional configuration interaction calculations as well as experimental measurements.