Accession Number : ADA261596


Title :   Theoretical Treatment of Spin-Forbidden and Electronically Nonadiabatic Processes. Methods and Applications


Descriptive Note : Final rept. 1 Nov 1989-31 Oct 1992


Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF CHEMISTRY


Personal Author(s) : Yarkony, David R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a261596.pdf


Report Date : 10 Jan 1993


Pagination or Media Count : 23


Abstract : This research program focusses on the electronic structure aspects of radiationless decay processes related to the stability and formation of high energy density materials. We have also begun theoretical studies on electronic nonadiabaticity in ion-molecule reactions. These studies are enabled by a unique system of electronic structure algorithms, the BROOKLYN programs, which we have developed over the last decade. These programs provide advanced capabilities for the study of the electronic structure aspects of spin-forbidden and spin-allowed electronically nonadiabatic processes. The methodology we have developed is based exclusively on large scale configuration state function expansions (10(5)- 10(6) terms). These methods, which we believe define the state of the art in these areas, have permitted us to make significant contributions to the understanding of electronically nonadiabatic processes. Problems of particular relevance to the high energy density materials program include studies of the stability of the potential energetic species a-N202, tetrahedral N4 and the dication HS2+. We have also initiated a research program in ion-molecule chemistry reporting for the first time a seam of crossings of two states of the same symmetry for the prototypical charge transfer reaction H+ + NO yields H + NO+. Finally a new phase of program development has been initiated with the goal of extending our capabilities for the direct determination of actual/allowed/ avoided crossing hyperlines and hyperplanes. The algorithms under development will permit systematic determination of (1) actual/allowed crossing seams passing through a minimum energy crossing point and (2) avoided crossing seams as a function of an arbitrary set of internal coordinates.


Descriptors :   *ELECTRONIC STATES , *DECAY , *ION MOLECULE INTERACTIONS , ALGORITHMS , ELECTRONICS , IONS , DENSITY , METHODOLOGY , STABILITY , STATE OF THE ART , SCALE , CROSSINGS , TRANSFER , EXPANSION , CHARGE TRANSFER , YIELD , SYMMETRY , COORDINATES , CONFIGURATIONS , INTERNAL , DETERMINATION , TOOLS , MOLECULES , MATERIALS , ENERGY , PHASE , HIGH ENERGY , CHEMISTRY


Subject Categories : Electrical and Electronic Equipment
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE