- Department of Chemistry, University of Newcastle upon Tyne, England
- Department of Chemistry, Lakehead University, Ontario, Canada
The absorption and emission of energy in the range lO Å to about 10 000 Å is almost entirely restricted to changes in electronic energy with accompanying vibrational and rotational energy changes. Unlike the microwave, infrared, and Raman changes there is no simple criterion as to whether a molecule may exhibit an electronic spectrum. The criterion is very difficult to evaluate and involves a number of approximations.