Accession Number:

ADA399546

Title:

Theoretical Determination of Optimized Structures for Molecular Complexes and Clusters

Descriptive Note:

Final rept. 1 Nov 1997-31 Oct 2000

Corporate Author:

ARKANSAS UNIV FAYETTEVILLE DEPT OF CHEMISTRY AND BIOCHEMISTRY

Personal Author(s):

• Pulay, Peter
• Baker, Jon

Report Date:

2002-02-14

Pagination or Media Count:

18.0

Abstract:

Our original proposal was in two parts. The first involved improved optimization methods for clusters and weakly interacting systems. Traditional optimization methods do not take into account the special character of these systems, such as the large disparity between the forces within and between molecules, and are thus inefficient. Our aim here was to develop an efficient optimization procedure for weakly interacting molecular clusters, as well as for other non-standard optimization scenarios, such as molecular adsorption on a model surface. The second project dealt with improved electronic structure methods for large molecular systems. The main thrust here was the development of efficient algorithms for the computation of both canonical and local MP2 energies and gradients. Current density functionals are not able to adequately model dispersion forces and MP2 should be a good option here. These latter calculations can eventually supply molecular energies and gradients for the optimization project. We have also developed a preliminary version of an atom-centered fast multipole program for large-molecule DFT calculations.

Descriptors:

• *OPTIMIZATION
• *CLUSTERING
• *MOLECULAR STRUCTURE
• *MOLECULAR COMPLEXES
• ALGORITHMS
• ADSORPTION
• CURRENT DENSITY

Subject Categories:

• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE