Diffusion-controlled reaction kinetics. Equivalence of the particle pair approach of Noyes and the concentration gradient approach of Collins and Kimball

Naqvi, K. Razi; Mork, K. J.; Waldenstrøm, S.

doi:10.1021/j100448a005

Cited by 44 publications

(14 citation statements)

References 2 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3,15,16,24,42 However, if primary recombination is slow enough that the scavenger can intervene, h(t) must be redefined to include primary recombination. The overall function is directly available from our experiment and the models used to fit the data.…”

Section: Reconsidering the Limiting Scavenging Yieldmentioning

confidence: 99%

Time-resolved scavenging and recombination dynamics from I:e− caged pairs

Kloepfer¹,

Vilchiz²,

Lenchenkov³

et al. 2002

The Journal of Chemical Physics

130

View full text Add to dashboard Cite

The competition between geminate recombination of electrons with their parent radicals and electron scavenging with H+ is directly time resolved with ∼100 fs resolution at several acid concentrations. Electrons were produced from iodide photodetachment or two-photon ionization of H2O. With regards to those produced from iodide photodetachment, the separation between primary and secondary I:e− recombination is established using a full numerical solution to the diffusion equation. Electron ejection is found to be short range and a potential well of ∼3kbT depth stabilizing the solvent caged pair is required to yield a satisfactory fit to experiment. From time-resolved scavenging data up to 5 M HCl, it is shown that the electron can be scavenged both inside and outside the caged pair by H+ with nearly equal efficiency. The steady-state scavenging yield as a function of scavenger concentration is then predicted based on the determined time-dependent recombination function. Reassessment of several benchmark scavenging experiments from the 1960’s leads to the conclusion that the primary yield of electrons after excitation of iodide is near unity.

show abstract

Section: Reconsidering the Limiting Scavenging Yieldmentioning

confidence: 99%

Time-resolved scavenging and recombination dynamics from I:e− caged pairs

Kloepfer¹,

Vilchiz²,

Lenchenkov³

et al. 2002

The Journal of Chemical Physics

130

View full text Add to dashboard Cite

show abstract

“…To apply the IRT method, we need to be able to invert this function for t, which is not as simple as inverting eq 21 for totally diffusion-controlled reactions. We have devised two methods of doing this.…”

Section: -(4d't)1f2 + 7 (D'r)'fzmentioning

confidence: 99%

Stochastic modeling of partially diffusion-controlled reactions in spur kinetics

Pimblott¹,

Green²

1992

J. Phys. Chem.

View full text Add to dashboard Cite

Stochastic simulation techniques have been developed for modeling partially diffusion-controlled reactions in spur kinetics. These methods have been used to examine whether deviation from full diffusion control influences the overall spur chemistry.Studies of idealized two-species spurs suggest that the time dependence of the kinetics is not affected by the nature of the reaction; however, the overall chemistry of a spur can be influenced by a deviation from full diffusion control as whether the reaction is fully or merely partially diffusion controlled can have a sisnificant effect on the initial overlap of the reactants. The reaction at time zero, which depletes the yield of reactants, is determined by the relative values of the width of the spur and of the encounter radius. This depletion is of particular importance in the radiation chemistry of water where the spatial distribution of the hydroxyl radical in a spur is believed to be significantly tighter than the distribution of the hydrated electron.

show abstract

“…A reaction would only occur when the distance of the reactants was no greater than its reaction radius. In our package, the radius R of a specific reaction was calculated based on its relationship with the reaction rate constant k , according to the Smoluchowski formalism (Naqvi et al , 1980):…”

Section: Methodsmentioning

confidence: 99%

Accelerated Monte Carlo simulation on the chemical stage in water radiolysis using GPU

2017

View full text Add to dashboard Cite

The accurate simulation of water radiolysis is an important step to understand the mechanisms of radiobiology and quantitatively test some hypotheses regarding radiobiological effects. However, the simulation of water radiolysis is highly time consuming, taking hours or even days to be completed by a conventional CPU processor. This time limitation hinders cell-level simulations for a number of research studies. We recently initiated efforts to develop gMicroMC, a GPU-based fast microscopic MC simulation package for water radiolysis. The first step of this project focused on accelerating the simulation of the chemical stage, the most time consuming stage in the entire water radiolysis process. A GPU-friendly parallelization strategy was designed to address the highly correlated many-body simulation problem caused by the mutual competitive chemical reactions between the radiolytic molecules. Two cases were tested, using a 750 keV electron and a 5 MeV proton incident in pure water, respectively. The time-dependent yields of all the radiolytic species during the chemical stage were used to evaluate the accuracy of the simulation. The relative differences between our simulation and the Geant4-DNA simulation were on average 5.3% and 4.4% for the two cases. Our package, executed on an Nvidia Titan black GPU card, successfully completed the chemical stage simulation of the two cases within 599.2 s and 489.0 s. As compared with Geant4-DNA that was executed on an Intel i7-5500U CPU processor and needed 28.6 h and 26.8 h for the two cases using a single CPU core, our package achieved a speed-up factor of 171.1-197.2.

show abstract

Diffusion-controlled reaction kinetics. Equivalence of the particle pair approach of Noyes and the concentration gradient approach of Collins and Kimball

Cited by 44 publications

References 2 publications

Time-resolved scavenging and recombination dynamics from I:e− caged pairs

Time-resolved scavenging and recombination dynamics from I:e− caged pairs

Stochastic modeling of partially diffusion-controlled reactions in spur kinetics

Accelerated Monte Carlo simulation on the chemical stage in water radiolysis using GPU

Contact Info

Product

Resources

About