Ab Initio Molecular Dynamics Above the Ionization Threshold
Abstract
The density of electrons in the ionosphere affects the propagation of radio waves used forcommunication and radar, and chemical release is a viable strategy to achieve local control of thisdensity. In order to achieve such control, the Air Force requires a quantitative understanding ofendothermic dissociative recombination (EDR), a poorly understood class of chemical reactionsthat occur when free electrons recombine with strongly bound molecular cations. Such reactionsinvolve dynamics in a dense manifold of diverse, high-energy electronic states, the relativeimportance of which can be difficult to predict a priori. We propose to develop a novel ab initiomolecular dynamics (AIMD) approach capable of modeling these dynamics without priorknowledge of the nature of the electronic states involved. Our approach will be based on a flexibletime-dependent configuration interaction description of the electronic structure and a mean-fielddescription of coupled electron-nuclear dynamics that incorporates decoherence effects accuratelyand efficiently. The development of software accelerated by graphics processing units, high performance computer processors designed for video games rather than science, will allow us tostudy more complex systems over longer time scales than would otherwise be possible. Thesenew AIMD tools will be applied to determine the mechanisms and energy-dependent cross sectionsof several EDR reactions, including that of SmO+, a reaction that plays a role in recent Air Forcechemical release experiments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 09, 2018
- Source ID
- FA95501710411
Entities
People
- Benjamin G Levine
Organizations
- Air Force Office of Scientific Research
- Michigan State University
- United States Air Force