Configuration Interaction and Absorption Spectra of Gases

Abstract

In special cases eigenstates of an atomic system existing in parallel can influence one another by configuration interaction. This leads to a characteristic change of the absorption spectrum, which can be calculated with the aid of a unitary transformation. The transformation leaves the total transition probability of the spectrum invariant, a condition which is not fulfilled in calculations of preceding papers. This comes from the fact that nonconverging expressions are used in calculating the total transition probability. Assumptions are given here by which the convergence of the corresponding expressions is achieved, thus causing the total transition probability to be invariant. From this follow modifications in the calculation of the average absorption coefficient of auto-ionizing term series. As an example, a precise examination of the absorption spectrum of xenon between the two ionization limits $P_{\frac{3}{2}}$ and $P_{\frac{1}{2}}$ is given. This shows that the experimental average absorption coefficient is in good agreement with the theoretical considerations.