Incorporation of quantum effects in generalized-transition-state theory

Truhlar, Donald G.; Isaacson, Alan D.; Skodje, Rex T.; Garrett, Bruce C.

doi:10.1021/j100209a021

Cited by 283 publications

(212 citation statements)

References 5 publications

(8 reference statements)

Supporting

Mentioning

206

Contrasting

Unclassified

Order By: Relevance

“…This com parison of semiclassical fixed-energy three-dimensional results with accurate ones is consistent with expectations based on previous comparisons of ther mally averaged semiclassical rate coefficients with ap proximate quantum ones [37] and with comparisons of semiclassical collinear thermal rate constants with accurate quantal ones in the same dimensionality [3]. Since the semiclassical calculations are applicable to systems with many degrees of freedom [29, [55][56][57][58][59][60][61] their good agreement with accurate quantal results bodes well for our ability to predict quantum effects on kinetic isotope effects involving tunneling in many systems of interest.…”

Section: Quantum Mechanical Calculationssupporting

confidence: 77%

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD

Lynch

Halvick

Truhlar

et al. 1989

Zeitschrift Für Naturforschung A

Self Cite

View full text Add to dashboard Cite

S e m ic la s s ic a l a n d Q u a n tu m M e c h a n ic a l C a lc u la tio n s o f Is o to p ic K in e tic B ra n c h in g R a tio s f o r th e R e a c tio n o f 0 ( 3P ) w ith H D Dedicated to Professor Jacob Bigeleisen on the occasion of his 70th birthday Tunneling probabilities for the reactions O + HD ->OH + D and O + DH ->OD + H have been calculated by semiclassical dynamical methods and compared to accurate quantal calculations for the same potential energy surface. The results are used to test the reliability of variational transition state theory with the least-action semiclassical method for tunneling probabilities for the prediction of intramolecular kinetic isotope effects.

show abstract

Section: Quantum Mechanical Calculationssupporting

confidence: 77%

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD

Lynch

Halvick

Truhlar

et al. 1989

Zeitschrift Für Naturforschung A

Self Cite

View full text Add to dashboard Cite

show abstract

“…The canonical variational theory (CVT) [64][65][66][67][68][69][70] is an extension of the transition-state theory (TST). [80,81] This theory minimizes the errors due to recrossing trajectories [82][83][84] by moving the dividing surface along the MEP to minimize the rate. The reaction coordinate (s) represents the distance along the MEP in an isoinertial mass-scaled coordinate system with a scaling mass equal to 1 amu.…”

Section: Methodsmentioning

confidence: 99%

Mechanism and Kinetics of the Reaction of OH Radicals with Glyoxal and Methylglyoxal: A Quantum Chemistry+CVT/SCT Approach

et al. 2004

View full text Add to dashboard Cite

A theoretical study of the mechanism and kinetics of the OH hydrogen abstraction from glyoxal and methylglyoxal is presented. Optimum geometries, frequencies, and gradients have been computed at the BHandHLYP/6-311++G(d,p) level of theory for all the stationary points, as well as for 12 additional points along the minimum energy path (MEP). Energies were obtained by single-point calculations at the above geometries using CCSD(T)/ 6-311++G(d,p) to produce the potential energy surface. The rate coefficients were calculated for the temperature range 200-500 K by using canonical variational theory (CVT) with small-curvature tunneling (SCT) corrections. Our analysis suggests a stepwise mechanism, which involves the formation of a reactant complex. The overall agreement between the calculated and experimental kinetic data is very good. This agreement supports the reliability of the Arrhenius parameters of the glyoxal + OH reaction that are proposed in this work for the first time. The Arrhenius expressions that best describe the studied reactions are k1 = (9.63 +/- 0.23) x l0(-13)exp[(517 +/- 7)/T] and k2 = (3.93 +/- 0.11) x 10(-13)exp[(1060 +/- 8)/T]cm3 molecule(-1)s(-1) for glyoxal and methylglyoxal, respectively.

show abstract

“…47,76 To do this, the vibrational modes along the reaction coordinate are first correlated as dis-Ž cussed later see ''Technical Considerations'' in . Appendix A .…”

Section: Vibrational-state-selected Reactionsmentioning

confidence: 99%

TheRate: Program forab initio direct dynamics calculations of thermal and vibrational-state-selected rate constants

1998

View full text Add to dashboard Cite

We introduce TheRate (THEoretical RATEs), a complete application program with a graphical user interface (GUI) for calculating rate constants from first principles. It is based on canonical variational transition‐state theory (CVT) augmented by multidimensional semiclassical zero and small curvature tunneling approximations. Conventional transition‐state theory (TST) with one‐dimensional Wigner or Eckart tunneling corrections is also available. Potential energy information needed for the rate calculations are obtained from ab initio molecular orbital and/or density functional electronic structure theory. Vibrational‐state‐selected rate constants may be calculated using a diabetic model. TheRate also introduces several technical advancements, namely the focusing technique and energy interpolation procedure. The focusing technique minimizes the number of Hessian calculations required by distributing more Hessian grid points in regions that are critical to the CVT and tunneling calculations and fewer Hessian grid points elsewhere. The energy interpolation procedure allows the use of a computationally less demanding electronic structure theory such as DFT to calculate the Hessians and geometries, while the energetics can be improved by performing a small number of single‐point energy calculations along the MEP at a more accurate level of theory. The CH4+H↔CH3+H2 reaction is used as a model to demonstrate usage of the program, and the convergence of the rate constants with respect to the number of electronic structure calculations. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 1039–1052, 1998

show abstract

Incorporation of quantum effects in generalized-transition-state theory

Cited by 283 publications

References 5 publications

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD

Mechanism and Kinetics of the Reaction of OH Radicals with Glyoxal and Methylglyoxal: A Quantum Chemistry+CVT/SCT Approach

TheRate: Program forab initio direct dynamics calculations of thermal and vibrational-state-selected rate constants

Contact Info

Product

Resources

About

Incorporation of quantum effects in generalized-transition-state theory

Cited by 283 publications

References 5 publications

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(3P) with HD

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(3P) with HD

Mechanism and Kinetics of the Reaction of OH Radicals with Glyoxal and Methylglyoxal: A Quantum Chemistry+CVT/SCT Approach

TheRate: Program forab initio direct dynamics calculations of thermal and vibrational-state-selected rate constants

Contact Info

Product

Resources

About

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD

Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reactionof O(³P) with HD