Accession Number : ADA334924

Title :   Isomerization Reaction Surfaces: Quantum Mechanical Studies of Triplet C2H2, Singlet AlHO and Singlet C2H2O

Descriptive Note : Final rept.

Corporate Author : AIR FORCE RESEARCH LAB BOLLING AFB DC

Personal Author(s) : Vacek, George R.

PDF Url : ADA334924

Report Date : 1995

Pagination or Media Count : 101

Abstract : High-level ab initio molecular electronic structure theory has been utilized to investigate specific isomerization reaction surfaces including the triplet acetylene and vinylidene potential energy (PE) hypersurface, the X-tilde HAlO and AlOH PE hypersurface and the X-tilde oxirene potential energy minima. Basis sets as large as triple zeta plus two sets of polarization functions augmented with higher angular momentum functions TZ(2df,2pd) have been utilized in conjunction with correlated methods as sophisticated as the coupled cluster approach including all single, double and perturbative triple excitations CCSD(T). Of particular interest are predictions of the activation energies, zero-point vibrational energy (ZPVE) corrected barriers for rearrangement, of a-tilde 3B2 vinylidene to b-tilde 3Bu trans-bent acetylene and of cis-bent a 3B2 acetylene to trans-bent b-tilde 3Bu acetylene. The physical properties of a-tilde 3B2 vinylidene, including the dipole moment, harmonic vibrational frequencies and the infrared intensities, have also been reported. The activation energy and Delta E from X-tilde HAlO to X-tilde AlOH is predicted. Some molecular properties of HAlO and AlOH in their equilibrium geometries useful for experimental identification purposes are also given.

Descriptors :   *QUANTUM CHEMISTRY, *ACETYLENE, *ISOMERIZATION, COUPLING(INTERACTION), FREQUENCY, ELECTRONICS, POLARIZATION, VIBRATION, COMPUTATIONS, PHYSICAL PROPERTIES, QUANTUM THEORY, HARMONICS, INTENSITY, THESES, EQUILIBRIUM(GENERAL), SURFACES, CLUSTERING, ALUMINUM, CHEMICAL REACTIONS, BARRIERS, MOLECULAR STRUCTURE, POTENTIAL ENERGY, INFRARED RADIATION, MOLECULAR PROPERTIES, HYDROXIDES, ANGULAR MOMENTUM, VINYL PLASTICS, DIPOLE MOMENTS, ACTIVATION ENERGY, KETENES.

Subject Categories : Physical Chemistry
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE