These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
revised on 07.08.2019, 14:19 and posted on 07.08.2019, 20:22by David Lingerfelt, Panchapakesan Ganesh, Jacek Jakowski, Bobby Sumpter
A time dependent self consistent field based method for determining the rates of electronic excitations induced in materials by the presence of external point charges is presented. The method utilizes the full scalar potential of the external point charge in the interaction Hamiltonian instead of relying on multipolar expansions thereof. A general method is presented for determining the conditions under which dipole selection rules are adequate to describe the electronic response of the material to perturbation by external point charges. The position dependence of point charge induced transition rates between the ground and lowest few excited electronic states was resolved for a small polybenzoid. Notably, electronic excitations that are optically forbidden can be strongly allowed for particular positions of the perturbing point charge. Application of the methods detailed here can lead to an improved understanding of the electronic response of materials under irradiation by beams of charged particles.