The nonlocal density -functional analysis of potential energy surfaces

• Main Author: Mar, Perry Louis
• Language: ENG
• Published: ScholarWorks@UMass Amherst 2000
• Subjects: Chemical engineering|Chemistry
• Online Access: https://scholarworks.umass.edu/dissertations/AAI9960769

Nonlocal density-functional theory has been applied to two chemical reaction systems of engineering interest, the HO2 system and the CH 2O2 system, in order to better understand the relative roles of different levels of density-functional theory in exploring complete reactive pathways, to explore the potential energy surfaces in greater detail than that obtained in previous work, and to validate the computational implementation. The HO2 system undergoes one of the most important elementary reactions in combustion, H + O2 → O + OH. The CH2O2 system undergoes the water-gas shift reaction, CO + H2O → CO2 + H2. Nonlocal capabilities as well as additional local methods were incorporated into the computational implementation. The application of nonlocal methods resulted in substantial improvements in accuracy over that from the use of local methods alone. A novel method for visualizing energy profiles of reaction systems has also been invented. This method is general in its application in the sense that it treats energy profiles involving arbitrary points in configuration space, including the important case of multiple reaction paths.