In
chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
, dynamic Monte Carlo (DMC) is a
Monte Carlo method for modeling the dynamic behaviors of
molecules by comparing the rates of individual steps with
random numbers. It is essentially the same as
Kinetic Monte Carlo. Unlike the
Metropolis Monte Carlo method, which has been employed to study systems at
equilibrium, the DMC method is used to investigate non-equilibrium systems such as a
reaction,
diffusion, and so-forth (Meng and Weinberg 1994). This method is mainly applied to analyze adsorbates' behavior on surfaces.
There are several well-known methods for performing DMC simulations, including the First Reaction Method (FRM) and Random Selection Method (RSM). Although the FRM and RSM give the same results from a given model, the
computer resources are different depending on the applied system.
In the FRM, the reaction whose time is minimum on the event list is advanced. In the event list, the tentative times for all possible reactions are stored. After the selection of one event, the system time is advanced to the reaction time, and the event list is recalculated. This method is efficient in
computation time because the reaction always occurs in one event. On the other hand, it consumes a lot of
computer memory because of the event list. Therefore, it is difficult to apply to large-scale systems.
The RSM decides whether the reaction of the selected molecule proceeds or not by comparing the transition probability with a
random number. In this method, the reaction does not necessarily proceed in one event, so it needs significantly more computation time than FRM. However, this method saves computer memory because it does not use an event list. Large-scale systems are able to be calculated by this method.
See also
*
Hybrid Monte Carlo The Hamiltonian Monte Carlo algorithm (originally known as hybrid Monte Carlo) is a Markov chain Monte Carlo method for obtaining a sequence of random samples which converge to being distributed according to a target probability distribution for ...
References
* (Meng and Weinberg 1994): B. Meng and W. H. Weinberg, J. Chem. Phys. 100, 5280 (1994)
* (Meng and Weinberg 1996): B. Meng, W.H. Weinberg, Surface Science 364 (1996) 151-163.
Monte Carlo methods
Computational chemistry
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