Lattice dynamics history

The history of gas hydrate research, its physical and thermodynamics properties, and the impact on energy and the environment have been presented in several excellent books and reviews.This chapter is focused on the molecular aspect, particularly, on the application of different computational methods to investigate structural and thermodynamic stability, guest and lattice dynamics, thermal transport and mechanisms for homogeneous and heterogeneous crystallization. Even within this restricted choice of topics, there are numerous contributions to the modelling of hydrate properties. This chapter is not intended to provide a comprehensive review on the field of computational gas hydrate research. Even within the topics chosen no attempt was made to exhaustively review available literatures and competing theories. Rather, the... 

There has been a long history in theoretical efforts to understand H + H/Cu(lll) and its isotopic analogs because it represents the best studied prototype of an ER/HA reaction. These have evolved from simple 2D collinear quantum dynamics on model PES [386] to 6D quasi-classical dynamics on PES fit to DFT calculations [380,387,388], and even attempts to include lattice motion on ER/HA reactions [389]. These studies show that there is little reflection of incident H because of the deep well and energy scrambling upon impact, i.e., a % 1. Although some of the... 

To develop the kinetic equations in condensed phases the master equation must be formulated. In Section 3 the master equation is used to generate the kinetic equations for local concentrations and pair correlation functions. The latter set of equations permits consideration of history of formation of the local solid structure as well as its influence on the subsequent elementary stages. The many-body problem and closing procedure for kinetic equations are discussed. The influence of fast and slow stages on a closed system of equations is demonstrated. The multistage character of the kinetic processes in condensed phase creates a problem of self-consistency in describing the dynamics of elementary stages and the equilibrium state of the condensed system. This problem is solved within the framework of a lattice-gas model description of the condensed phases. 

Thus, investigations of the spin-lattice relaxation rates in the water system showed directly that water by its nature is a metastable liquid. The degree of binding of its molecules depends essentially on the past history of the water system involved, and therefore in studies of dynamic parameters one has to take into account the metastable structural state of the water system. The water structure is considerably determined by atmospheric gases. Their removal from water without distortion of its structure results in the ordering of intermolecular interactions (water structuring), whereas bubbling with air, on the contrary,... 

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