Spectral Theory of Physical and Chemical Binding: Aspects of Computational Implementation

Abstract

Progress is reported in the development and implementation of a spectral method for constructing the adiabatic electronic potential energy surfaces of large heterogeneous aggregates of physically or chemically interacting atoms. The work carries forward a program of study initiated some years ago by W. Moffitt to describe aggregate electronic structure solely in terms of the properties of atoms and their pairwise interactions. Necessary and sufficient conditions are described for construction of the transformation from diatomic to spectral-product states, and of the corresponding pair-interaction Hamiltonian matrices required in the development, employing representatives of the diatomic spectral response operator obtained from Fourier expansion of the Coulombic interactions. These conditions help to advance the development of the spectral method as a practical computational tool for electronic structure determinations employing conventional irreducible-symmetry methodology. The approach is illustrated with computational studies of avoided crossings in the potential energy surfaces of small van der Waals bonded NaAr(sub N) aggregates, which serve as useful prototypes for understanding selected attributes of cryogenic high energy density matter (HEDM). An outline is provided of work in progress on general implementation of the spectral method and of its application to cryogenic fuels and oxidizers seeded with trace metals which may exhibit improved combustion performance.

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Document Details

Document Type
Technical Report
Publication Date
Feb 24, 1998
Accession Number
ADA397877

Entities

People

  • J. Boatz
  • J. Sheehy
  • P. W. Langhoff

Organizations

  • Indiana University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption Spectra
  • Additives (Chemicals)
  • Air Force
  • Air Force Research Laboratories
  • Atoms
  • Chemical Reactions
  • Chemistry
  • Construction
  • Coordinate Systems
  • Crossings
  • Diatomic Molecules
  • Eigenvalues
  • Electrons
  • Energy
  • High Energy
  • Potential Energy
  • Propulsion Systems

Fields of Study

  • Physics

Readers

  • Quantum Chemistry
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Software Engineering

Technology Areas

  • Microelectronics