Molecular cluster calculations of cross-luminescence in BaF2, CsF, CsCl and CsBr

The structure in the cross-luminescence spectra of BaF2, CsF, CsC1 and CsBr has been explained by ab initio calculations using a molecular cluster approach in the Hartree-Fock approximation. The relaxation of the lattice on excitation of the cation valence shell strongly affects the calculated transition probabilities. For the relaxed lattices, the calculated transition times are found to be too short but the line structure is in better agreement with experiment than in the case of the undistorted lattice. (author)