Knowledge Bank

The electronic moments and rotational line intensity factors for diatomic molecules are directly related, through the line strength, to the transition probability or Einstein A-coefficient. Thus, when either the transition moments of the intensity factors are difined, in any manner, the other is necessarily determined also. Because there is no right” way to make these definitions, several different choices appear in the literature, often without the necessary clarifying descriptions. As a result, nearly everyone involved in quantitative radiative intensity research has struggled with the ubiquitous factors-of-two that are present in this work. This problem is discussed in some detail and the question is posed as to whether or not sufficient interest exist to warrant initiating a study to identify a reasonable set of standard” definitions.