We consider for bimolecular recombination reactions the K-adiabatic versus the K-active forms of RRKM theory, where K is the component of the total angular momentum along the axis of least moment of inertia of the recombination product. When that product is approximately a prolate symmetric top, with two moments of inertia of the product substantially larger than the third, K becomes a dynamica...

The bond dissociation kinetics of tethered atomic (Morse potential) chains under tensile stress is studied. Both RRKM (fully anharmonic, Monte Carlo) and RRK (harmonic appproximation) theory are applied to predict bond dissociation rate constants as a function of energy and tensile force. For chains with N P 3 atoms a hybrid statistical theory is used involving a harmonic approximation for moti...

A theory that describes the non-RRKM (non-Rice-Ramsperger-Kassel-Marcus) effects in the lifetime statistics of activated ozone molecules is derived. The non-RRKM effects are shown to originate due to the diffusive energy exchange between vibrational and rotational degrees of freedom in ozone molecule. The lifetime statistics is found to be intramolecular diffusion controlled at long times. The ...

The Rice–Ramsperger–Kassel–Marcus (RRKM) theory provides a simple yet powerful rate for calculating microcanonical constants. In particular, it has found widespread use in combination w...

In the pioneering work by R. A. Marcus, solvation effect on electron transfer (ET) processes was investigated, giving rise to celebrated nonadiabatic ET rate formula. this work, basis of thermodynamic potentials analysis, we reexamine Marcus' formula with respect Rice-Ramsperger-Kassel-Marcus (RRKM) theory. Interestingly, obtained RRKM analogue, which recovers original that is in a linear scena...

Intermediate and transition state energies have been calculated for the O + C3H6 (propene) reaction using the compound ab initio CBS-QB3 and G3 methods in combination with density functional theory. The lowest lying triplet and singlet potential energy surfaces of the O-C3H6 system were investigated. RRKM statistical theory was used to predict product branching

The mechanism for OH and NO3 radical-initiated oxidation reactions of methyl methacrylate (MMA) was investigated by using density functional theory (DFT) molecular orbital theory. Geometrical parameters of the reactants, intermediates, transition states, and products were fully optimized at the B3LYP/6-31G(d,p) level. Detailed oxidation pathways were presented and discussed. The rate constants ...

The most commonly used theoretical models for describing chemical kinetics are accurate in two limits. When relaxation is fast with respect to reaction time scales, thermal transition state theory (TST) is the theoretical tool of choice. In the limit of slow relaxation, an energy resolved description like RRKM theory is more appropriate. For intermediate relaxation regimes, where much of the ch...

Investigations on the dissociation kinetics of hydrated protonium ions, (H(2)O)(2)H(+) and their deuterated species (D(2)O)(2)D(+), are reported based on the harmonic and anharmonic oscillator model using the transition state theory and ab initio calculations. We find that the dissociation of (H(2)O)(2)H(+) and (D(2)O)(2)D(+) exhibits a distinct threshold behavior due to the existence of activa...