Polyatomic reaction dynamics

Zhang J Z H 1999 The semirigid vibrating rotor target model for quantum polyatomic reaction dynamics J. 

Truhlar, D. G. and Steckler, R. Potential energy surfaces for polyatomic reaction dynamics, Chem. Rev., 87(1987), 217-236... 

Several approaches to obtaining both qualitative and quantitative information on polyatomic reaction dynamics via reaction path potentials have been discussed by Miller [13], Truhlar and Gordon [14], Kraka and Dunning [1], Collins [15] and Hammes-SchifFer [16]. 

Finally, time dependent methods are yielding interesting views on polyatomic reaction dynamics, although not actually leading to the full state-to-state information. Most promising for the future will be the blending of these methods with the hyperspherical approach under focus in the present paper. 

Mathematical and Physical Sciences, Vol. 170, D. C. Clary, Ed., D. Reidel, Boston, 1986, pp. 27—45. Reaction Path Models for Polyatomic Reaction Dynamics—From Transition State Theory to Path Integrals. 

REACTION PATH MODELS FOR POLYATOMIC REACTION DYNAMICS— FROM TRANSITION STATE THEORY TO PATH INTEGRALS... 

REACTION PATH MODELS FOR POLYATOMIC REACTION DYNAMICS... 

Thus, the critical measure of the applicability of a method to polyatomic reaction dynamics is the scaling of its computational cost with respect to the number of basis functions or degrees of freedom. Since the standard time-independent scattering methods solve boundary-value problems, they scale as with the number of basis functions N, and are thus difficult to extend to large systems. Until a few years ago, the reduced-dimensionality approach (RDA) [32, 33] provided the only means for treating the four-atom reactive scattering problem in which a four-atom reaction system is reduced to an effective atom-diatom system through the elimi-... 

We believe that the TD approach currently provides the most viable means for carrying out accurate quantum dynamics studies of polyatomic reaction dynamics due to its relatively low scaling of computational cost with the number of basis function N [computing time (xN < oi < 2)] however, we need to further develop more efficient numerical treatments to make accurate... 

In addition to the reaction coordinate mapped out by the DRC, the minimum energy path from transition state to reactants or products is of interest. As with the DRC originating at the transition state, this path is coordinate-system independent. The calculation to determine the minimum energy path starts in a similar manner to the DRC calculation, only after the initial displacement, all velocities are annulled at every step. This results in the system moving perpendicular to the energy contours in mass-weighted coor nate space. Sutime independent, and are called intrinsic reaction coordinates (IRC). For a review of potential energy surfaces for polyatomic reaction dynamics, see ref. 59. 

D. G. Truhlar, R. Steckler, and M. S. Gordon, Chem. Rev., 87,217 (1987). Potential Energy Surfaces for Polyatomic Reaction Dynamics. 

With respect to a more quantitative characterization of the PE function along the reaction coordinate, in terms of local minima and barriers between them, the minimum energy reaction (MER) path concept is more promising. The MER path approach, also called the intrinsic reaction path approach [39], is defined as the steepest descent path from the transition state (a saddle point on the PE surface) down to the local minima that are equilibrium geometries of reactant and product. It has been shown [40] how to express the Hamiltonian of an N atom molecular system in terms of the reaction coordinate, and this approach has been used successfully to describe a variety of processes in polyatomic reaction dynamics. It is also well known that for many reactions (PT process among them) the MER path is very sharply curved, so that the relevant dynamical motion deviates far from it. This is not a particularly important point for our present purpose of a qualitative characterization of the PE surfaces relevant for the PT reaction, as far as we do not consider the dynamics of... 

Nyman G, Yu H-G (2012) Quantum approaches to polyatomic reaction dynamics. Int Rev... 

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