Quantum calculation of thermal rate constants for the H+D sub 2 reaction

Journal Article · Mon Jun 15 00:00:00 EDT 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.462242· OSTI ID:7300689

Park, T J ^[1]; Light, J C ^[2]

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1. Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712 (United States)
2. The Department of Chemistry and the James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

Thermal rate constants for the H+D{sub 2} reaction on the LSTH potential-energy surface are determined quantum mechanically over {ital T}=300--1500 K using the quantum flux--flux autocorrelation function of Miller (J. Chem. Phys. {bold 61}, 1823 (1974)). Following earlier works (T. J. Park and J. C. Light, J. Chem. Phys. {bold 91}, 974 (1989); T. J. Park and J. C. Light, {ital ibid}. {bold 94}, 2946 (1991)), we use the adiabatically adjusted principal axis hyperspherical coordinates of Pack (Chem. Phys. Lett. {bold 108}, 333 (1984)) and a direct product {ital C}{sub 2{ital v}} symmetry-adapted discrete variable representation to evaluate the Hamiltonian and flux. The initial representation of the {ital J}=0 Hamiltonian in the L{sup 2} basis of {similar to}14 000 functions is sequentially diagonalized and truncated to yield {similar to}600 accurate eigenvalues and eigenvectors for each symmetry species block. The {ital J}{gt}0 Hamiltonian is evaluated in the direct product basis of truncated {ital J}=0 eigenvectors and parity decoupled Wigner rotation functions. Diagonalization of the {ital J}{gt}0 Hamiltonian is performed separately for each {ital K}{sub {ital J}} block by neglecting Coriolis coupling and approximating {ital K} coupling by perturbation. Both eigenvalues and eigenvectors are corrected by the perturbation. Thermal rate constants for each {ital J}, {ital k}{sup {ital J}}({ital T}), are then determined by the flux--flux autocorrelation function considering nuclear spins. Due to the eigenvector corrections, both parity calculations are required to determine {ital k}{sup {ital J}}({ital T}). Overall thermal rate constants {ital k}({ital T}) are obtained by summing {ital k}{sup {ital J}}({ital T}) over {ital J} with the weight of 2{ital J}+1 up to {ital J}=30. The results show good agreement with experiments.

• DOE Contract Number: FG02-87ER13679
• OSTI ID: 7300689
• Journal Information: Journal of Chemical Physics; (United States), Vol. 96:12; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DEUTERIUM
ATOM-MOLECULE COLLISIONS
HYDROGEN
CHEMICAL REACTION KINETICS
CORRECTIONS
EIGENVECTORS
POTENTIAL ENERGY
QUANTUM MECHANICS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
THERMODYNAMICS
ATOM COLLISIONS
COLLISIONS
ELEMENTS
ENERGY
HYDROGEN ISOTOPES
ISOTOPES
KINETICS
LIGHT NUCLEI
MECHANICS
MOLECULE COLLISIONS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
REACTION KINETICS
STABLE ISOTOPES
TEMPERATURE RANGE
664300* - Atomic & Molecular Physics- Collision Phenomena- (1992-)
400201 - Chemical & Physicochemical Properties
661100 - Classical & Quantum Mechanics- (1992-)