Crystal-split electronic states of an atom in a rare gas crystal. Calculation of the absorption and fluorescence spectra of trapped oxygen (3P, 1D, 1S) atoms

A method is proposed to determine the (crystal perturbed) energy levels of a guest species at any point inside the trapping site of an inclusion distorted host crystal. It relies on available pair potential energy curves, usually deduced from ab initio data supplemented by long-range dispersion energy when necessary. It is applied here to oxygen in its atomlike 3P, 1D or 1S state imbedded in Ne, Ar, Kr, and Xe matrix and allows reproduction of transition energies within 0.03 eV, and other experimental features. Its broad field of application could find many other exploitations, some of which are proposed.