Potential Energy Surfaces and Dynamics of High Energy Materials

Abstract

On the theoretical side, a new highly scalable code for multi-configurational self-consistent field (MCSCF) calculations has been developed. This code is in the latest GAMESS release. A parallel code for second order unrestricted open shell perturbation theory (UMP2) gradients has been developed. The derivation for the Z-averaged open shell second order perturbation theory gradients has been completed, and a paper describing this derivation has been published. The parallel code for this method has now been completed. A new second order multi-reference perturbation theory (based on the generalized Van Vleck perturbation theory), GVVPT2 has been implemented in GAMESS. A preliminary code for the GVVPT2 gradients has been written, and a more robust code is in progress. The MCSCF analytic Hessian code has now been completed. Initial scaling tests suggest that this code, now available in GAMESS, will scale very well with the number of processors. A review paper on second-order perturbation theory gradients has been published. A new, very effective coarse-grained parallel method, called GDDI, has been developed and implemented. This method has already proved to be very effective for numerical gradient and Hessian calculations, since each energy or energy + gradient calculation is completely independent of each other. Other developments include the implementation of a new density functional theory (DFT)-based effective fragment potential (EFP) method, the development of molecular dynamics and Monte Carlo methods to facilitate the study of solvation and liquid behavior, and the development and implementation of several MCSCF-based approaches to spin-orbit coupling. With regard to applications, considerable progress has been made in our understanding of the mechanisms for formation of POSS (polyhedral oligomeric silsesquioxanes) and their titanium analogs. A paper on ionic liquids based on triazolium cation has been published.

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Document Details

Document Type
Technical Report
Publication Date
Aug 31, 2005
Accession Number
ADA444847

Entities

People

  • Mark S. Gordon

Organizations

  • Iowa State University

Tags

DTIC Thesaurus Topics

  • Chemistry
  • Computational Chemistry
  • Computational Chemistry Methods
  • Density Functional Theory
  • Electronic Structure Methods
  • Electronic Structure Theory
  • Electrons
  • High Energy
  • Ionic Liquids
  • Materials
  • Molecular Dynamics
  • Monte Carlo Method
  • Perturbation Theory
  • Potential Energy
  • Spin-Orbit Interaction
  • Students
  • Surface Chemistry

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Quantum Chemistry

Technology Areas

  • Space