Accession Number : ADA473091


Title :   New Tools for the Study of Combustion Chemistry and Complex Gas-Surface Interactions from First Principles


Descriptive Note : Final rept. 1 Jan 2004-30 Apr 2007


Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA PA RESEARCH SERVICES


Personal Author(s) : Rappe, Andrew M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a473091.pdf


Report Date : 06 Oct 2007


Pagination or Media Count : 15


Abstract : Molecular and radical chemisorption on ferroelectric oxides and on metals (Rh, Cu, Pt, Al, Pd, Ag) was studied with first-principles density functional theory (DFT). New methods were developed for computing the chemisorption energies of molecules to surfaces accurately within DFT. Oxide-supported metals were modeled as well, examining how oxide-metal bonding affects metal surface chemistry. Quantum Monte Carlo (QMC) calculations were performed on diatomic and polyatomic molecules, establishing the capability of computing atomic forces in molecules with QMC. Intermolecular interactions resulting from high molecular coverage were analyzed to understand saturation coverage. A direct dynamics approach was developed for computing the infrared emission signatures of combustion products, including vibrationally excited radicals and closed-shell molecules. The emission spectrum of vinyl radical C2H3 was computed and compared with recent experiments. It was demonstrated that molecular radicals stabilize ferroelectric polarization in BaTiO3 nanowires and PbTiO(sub-3) thin films. It was found that metal monolayers are significantly influenced by ferroelectric oxide supports, opening the possibility of switchable nanocatalysts.


Descriptors :   *CHEMISTRY , *COMBUSTION , *GAS SURFACE INTERACTIONS , *FIRST PRINCIPLES CALCULATIONS , *SOFTWARE TOOLS , POLYATOMIC MOLECULES , MOLECULE MOLECULE INTERACTIONS , FERROELECTRICITY , CHEMISORPTION , INFRARED SPECTRA , DIATOMIC MOLECULES , MONTE CARLO METHOD


Subject Categories : Physical Chemistry
      Numerical Mathematics


Distribution Statement : APPROVED FOR PUBLIC RELEASE