A contribution to the discussion on the relaxed excited F centre

Abstract
An interpretation is given of the behaviour of the relaxed excited F centre in terms of a hydrogenic model with broad wave functions. In particular the dependence is considered of the lifetime τ on the host crystalline matrix at a fixed low temperature, and on the temperature T for a given matrix. Precision experimental data are given for τ(T) in NaCl, RbCl, and KBr.