Prospects for first-principle calculations of scintillator properties

Several scintillation processes can be modeled from first principles using quantum chemistry cluster calculations and recently available high-performance computers. These processes include the formation of excitons and trapping centers, the diffusion of ionization energy (electrons and holes) through a host crystal, and the efficient capture of these carriers by an activator atom to form a luminous, non-quenched excited state. As examples of such calculations, results are presented for (1) hole transport in the known scintillator host crystal CsI, (2) hole trapping in the non-scintillator PbF2, (3) hole transport in the experimentally unexplored PbF4, and (4) the electronic nature of excited states of CsI : Tl and CsI : Na.