Approximate switching algorithms for trajectory surface hopping
نویسندگان
چکیده
Three approximate switching algorithms for trajectory surface hopping calculations are presented using simple models to describe the dependence of the hopping probability on the nonadiabatic coupling strength. The switching algorithms are applied to the calculation of the electronic deexcitation in ethylene, methaniminium ion and trans-azobenzene. Compared with the results from the standard fewest switching algorithm (FSA), the simplest approximation based on a local diabatic representation shows some qualitative failures and overestimates the decay times severely. The other two approximate switching algorithms incorporate stochastic features and reproduce the FSA results well, with a deviation of typically 20–30% in the computed decay times. They offer a simple and efficient description of the nonadiabatic dynamics of the investigated systems. 2008 Elsevier B.V. All rights reserved.
منابع مشابه
Coherent switching with decay of mixing: an improved treatment of electronic coherence for non-Born-Oppenheimer trajectories.
The self-consistent decay-of-mixing (SCDM) semiclassical trajectory method for electronically nonadiabatic dynamics is improved by modifying the switching probability that determines the instantaneous electronic state toward which the system decoheres. This method is called coherent switching with decay of mixing (CSDM), and it differs from the previously presented SCDM method in that the elect...
متن کاملNonadiabatic transition state theory and multiple potential energy surface molecular dynamics of infrequent events
Classical transition state theory ~TST! provides the rigorous basis for the application of molecular dynamics ~MD! to infrequent events, i.e., reactions that are slow due to a high energy barrier. The TST rate is simply the equilibrium flux through a surface that divides reactants from products. In order to apply MD to infrequent events, corrections to the TST rate that account for recrossings ...
متن کاملPropagation through Conical Crossings: an Asymptotic Semigroup
We consider the standard model problem for a conical intersection of electronic surfaces in molecular dynamics. Our main result is the construction of a semigroup in order to approximate the Wigner function associated with the solution of the Schrödinger equation at leading order in the semiclassical parameter. The semigroup stems from an underlying Markov process which combines deterministic t...
متن کاملApproximate Pareto Optimal Solutions of Multi objective Optimal Control Problems by Evolutionary Algorithms
In this paper an approach based on evolutionary algorithms to find Pareto optimal pair of state and control for multi-objective optimal control problems (MOOCP)'s is introduced. In this approach, first a discretized form of the time-control space is considered and then, a piecewise linear control and a piecewise linear trajectory are obtained from the discretized time-control space using ...
متن کاملSingle switch surface hopping for a model of pyrazine.
The single switch trajectory surface hopping algorithm is tested for numerical simulations of a two-state three-mode model for the internal conversion of pyrazine through a conical intersection of potential energy surfaces. The algorithm is compared to two other surface hopping approaches, namely, Tully's method of the fewest switches [J. Chem. Phys. 93, 1061 (1990)] and the method by Voronin e...
متن کامل