Abstract
Infrared and Zeeman infrared measurements of the tetragonal symmetry cerium fluoride ion and neodymium fluoride ion charge compensation sites in calcium and strontium fluoride are reported. The neodymium results are supplemented by optical absorption and fluorescence measurements. Crystal field analyses successfully account for the observed2F72/(4f1) and4I92/,4I112/(4f3) multiplet crystal field splittings and for the measured Zeeman splitting values.