Atomistic Simulation Methods

Figure 19. Methanol permeability as a function of temperature and diffusiv-ity data evaluated using the atomistic simulation method.138 Reprinted from Journal of Electrochemical Society, X. Zhou, Z. Chen, F. Delgado, D. Brenner, R. Srivastava, J. Electrochem. Soc. 154, B82 (2007)- Reproduced by permission of the Electrochemical Society.

Jayaraman and Maginn calculated two crystal polymorphs of [C4mim][Cl] using a thermodynamic integration-based atomistic simulation method [78]. The computed... 

In this context, Sayle et al. have used atomistic simulation methods to investigate the interaction of ceria with impurities, particularly rhodium, palladium and platinum. The energetics of the most common valence states for the metal atoms were investigated, as well as the variation of the energy of the impurities with depth below the surface and the tendency of defects to segregate to the surfaces. Fig. 8.9. shows the substitutional defect formation energies as a function of the distance from the (111) and (110) surfaces of Ce02 for C e " ", PcP+ and Sayle etal. found that... 

Just a few years ago, the limitations of solubility parameter calculations and measurements discussed above were serious impediments to modeling the phasic and interfacial behaviors of polymeric systems. The coming of age of atomistic simulation methods over the last few years has improved this situation dramatically. As discussed in Section 5.A.3, whenever accuracy is important in calculating the phasic or the interfacial behavior of a system, it is nowadays strongly preferable to use atomistic simulations employing modem force fields of the highest available quality instead of solubility parameters in order to estimate the Flory-Huggins interaction parameters (%) between the system components as input for further calculations. 

Empirical correlations [21] and computationally-intensive large-scale atomistic simulations [27-42] have been mentioned above as opposite extremes in the spectrum of methods used to treat diffusion phenomena. In addition, two general types of phenomenological theories (which are much more sophisticated than empirical correlations, but much more coarse-grained than atomistic simulation methods) have been developed to treat diffusion ... 

The particular complexities of zeolite framework structures have spawned a number of theoretical approaches directed towards their prediction and refinement. In this section we shall concentrate principally on some recent applications of atomistic simulation methods to the study of zeolite framework structure. However, it is appropriate first to give a brief survey of other theoretical advances in this field, which have for the most part been concerned with developing an understanding of framework structure from an empirical standpoint. Fuller details of these topics may be found in the previous reviews of Freeman et al. (1992) and Price et al. (1992). 

Bernstein N, Kermode JR, Csanyi G. Hybrid atomistic simulation methods for materials systems. Rep. Prog. Phys. 2009 72 026501. 

Abstract A variety of computational procedures used to predict properties of energetic materials is presented. These procedures, based on standard atomistic simulation methods, demonstrate the ability to predict key properties of these materials related to performance or hazard. Several applications of the various methods for nitrogen-rich materials are provided to illustrate capabilihes. Also, an overview of theoretical efforts in computational design of novel all-nitrogen materials is given. 

The theoretical methods that will be discussed in this chapter represent only a subset of the various atomistic simulation methods used in computational materials research, and we refer the interested reader to the various comprehensive reviews on each method [22-30]. For the purposes of this chapter, however, we will highhght important points associated with various theories in appUcation to the high nitrogen materials. 

Such ambitious tasks require the development of improved atomistic simulation methods and/or new mathematical approaches that enable the quick derivation of specific descriptors for non-covalent amorphous systems at low computational costs. 

Moreover, we have recently proposed and developed the hybrid Monte Carlo (MC)/Molecular Dynamics (MD) reaction method [70] to realize the practical atomistic simulation method for a massive complex chemical reacting systems. The concept of the hybrid MC/MD reaction method is shown in Fig. 8.16. First, we execute MD simulation in the region R until one (or some) pair of atoms meets the necessary conditions and select (instantaneous) configuration state r. Next, one of pairs is virtually reacted to generate a (instantaneous) configuration state s, relaxing... 

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