First Principles Calculations of the Adsorption of Nitromethane and 1,1-Diamino-2,2-dinitroethylene (FOX-7) Molecules on Al2O3(0001) Surface
Abstract
First-principles calculations based on density functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption of nitromethane (NM) and 1,1-diamino-2,2-dinitroethylene (FOX-7) molecules on the basal plane of an alpha-Al2O3 crystal. The calculations employ a (2x2) supercell slab model and 3D periodic boundary conditions. Based on these calculations we have determined that both NM and FOX-7 molecules can adsorb nondissociatively on the surface with the most stable adsorption configurations parallel to the surface. The binding energies are in the range 25.3-26.0 kcal/mol for NM and 35.6-48.3 kcal/mol for FOX-7 depending on the relative molecular orientation and the surface sites. The minimum energy pathways for NM dissociation have been determined and a low energy pathway leading to H-atom elimination with formation of adsorbed CH2NO2 and hydroxyl species has been identified. Additional calculations have focused on adsorption properties of aci-nitromethane tautomers and on description of the energetic pathways connecting adsorbed nitromethane molecule with these tautomers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2004
- Accession Number
- ADA433748
Entities
People
- Dan C. Sorescu
- Donald L. Thompson
- Jerry A. Boatz
Organizations
- Air Force Research Laboratory