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):

Report Date:

1993-01-10

Pagination or Media Count:

23.0

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 105- 106 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 actualallowed avoided crossing hyperlines and hyperplanes. The algorithms under development will permit systematic determination of 1 actualallowed crossing seams passing through a minimum energy crossing point and 2 avoided crossing seams as a function of an arbitrary set of internal coordinates.

Subject Categories:

  • Electrical and Electronic Equipment
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE