Accuracy of trajectory calculations and transition state theory for thermal rate constants of atom transfer reactions

Journal Article · Thu Jan 11 04:00:00 EST 1979 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100464a025· OSTI ID:6341772

Truhlar, D G

The reliability of several practical techniques for computing the equilibrium rate constant of elementary atom-transfer reactions is discussed. Conventional transition state theory and two generalizations, the canonical variational theory of reaction rates (also known as the method of free energy surfaces) and the adiabatic theory of reactions (also known as the microcanonical variational theory of reactions), are all considered. For these theories the transmission coefficient is set equal to unity as usual. In addition the quasi-classical trajectory method and three extensions, the quasi-classical trajectory method with quantum mechanical energetic threshold, the quasi-classical trajectory reverse histogram method, and the classical S matrix theory, are considered. Results of the application of these theories to compute thermal rate constants for collinear and three-dimensional systems where accurate quantal calculations are available are reviewed. The systems considered are H + H/sub 2/, Cl + H/sub 2/, H + Cl/sub 2/, F + H/sub 2/, H/sub 2/ + I, and isotopic analogues at 300 to 1500/sup 0/K. The comparisons discussed should allow more realistic estimates to be made of the errors in using these approximate theories to calculate thermal rate constants, isotope effects, and activation energies for chemical reactions. 76 references, 15 tables.

• Research Organization: Univ. of Minnesota, Minneapolis
• OSTI ID: 6341772
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 83:1; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
ACCURACY
ACTIVATION ENERGY
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHLORINE
COLLISIONS
CROSS SECTIONS
CRYOGENIC FLUIDS
ELEMENTS
ENERGY
FLUIDS
FLUORINE
HALOGENS
HIGH TEMPERATURE
HYDROGEN
IODINE
ISOTOPE EFFECTS
ISOTOPES
KINETICS
MATHEMATICAL MODELS
MECHANICS
MEDIUM TEMPERATURE
MOLECULE COLLISIONS
NONMETALS
QUANTUM MECHANICS
REACTION KINETICS
TEMPERATURE DEPENDENCE
VERY HIGH TEMPERATURE