Liquids significant structure theory

Significant Structure Theory and Eucken s Polymer Model. If we drop the restriction that the bulky species represent only Ice-I-like structures and reserve the term ice-like for water molecules which have merely the same spatial arrangement as ice (i.e., tetrahedrally hydrogen-bonded), we may include in this two-state theory (in which we have a bulky and a dense species) the treatment by Marchi and Eyring (107). This is a special case of the significant structure theory of liquids and introduces, as a specific element, fluidized vacancies in addition to the individual monomers (which, in turn, are assumed capable of free rotation). 

Sound Velocity and van der Waals Force in Liquids According to Significant Structure Theory... 

The significant structure theory of liquid has been one of the most widely applied of the various theories of liquids. It has been applied with success to predict the thermodynamic, dielectric, transport, and surface properties of many liquid systems ranging from simple liquids such as argon to complicated systems such as water or some mixtures. This model for liquids is based on several confirmed experimental facts and in this respect is the most acceptable of those currently offered. ... 

In this paper we discuss the further validity of the model by checking the velocities of sound and van der Waals forces in liquids. Since these properties are related to the second derivative of the partition function, their results will constitute a severe test of the model. According to the significant structure theory, the partition function of liquids can be expressed as follows ... 

Professor Eyring developed two irnportant theories one is the theory of rate processes and the other the significant structure theory of liquids. Many liquid theories have been reported. I cannot think of any other however, which gives a clearer picture of liquid than the significant structure theory and is more applicable to so many types of liquid. 

The significant structures theory as developed for liquids by Eyring, Ree, and collaborators is shown to be applicable also to the plastic crystal state. The properties of CBr (in the plastic crystal state) were calculated and compared with the experimental data. The calculations were performed on a digital computer using, without alteration, a program developed for the liquid state. 

Since the significant structures theory as used by Eyring and collaborators is able to predict quite accurately all the thermodynamic and many physical properties of a liquid using a model that assumes the volume expansion of a liquid to be due to the introduction of holes in the solid lattice, it seems quite likely that the theory might also be applied to the plastic crystal state. In order to test this idea, the theory was applied to the plastic crystal state of CBr4, for which good experimental data are available. ... 

It is seen that the accuracy of the calculated properties is quite good—in most cases somewhat better than the accuracy expected for similar calculations of liquids. It must be concluded, therefore, that the significant structures theory yields an adequate description of the plastic crystal state as well as the liquid state. 

SIGNIFICANT STRUCTURE THEORY OF BINARY LIQUID MIXTURES. CCL4 AND CYCLOHEXANE. 

THE SIGNIFICANT STRUCTURE THEORY OF VISCOSITY AND DIFFUSION IN LIQUIDS. 

PARTI. THE SIGNIFICANT STRUCTURE THEORY APPLIED TO LIQUID WATER AND HEAVY WATER. PART II. DIELECTRICAL PROPERTIES OF LIQUID WATER AND VARIOUS FORMS OF ICE. PART III. THE SIGNIFICANT STRUCTURE THEORY OF ISOMERIC EFFECTS. PH. D. THESIS. 

SIGNIFICANT STRUCTURE THEORY APPLIED TO SOME LIQUID ROCKET FUELS. 

LIQUID VISCOSITIES OF BINARY MIXTURES AND SOME HYDROCARBONS IN THE HIGH PRESSURE RANGE WITH APPLICATIONS OF THE SIGNIFICANT STRUCTURE THEORY. 

Vilcu R, Miscdolea C (1967) Significant- structure theory of liquids. Heat capacities, compressibilities, and thermal- expansion coefficients of some molten alkali halides. J Chem Phys 46 906-909... 

One interesting observation made in these model studies was the existence of regions of high density called pseudo-nuclei. When the nucleation processes involved in the change from liquid to sohd are considered (Chapter 2) the occurrence of ordered crystal-like regions (embryos) in the hquid is postulated. These pseudo-nuclei or the crystal-like components of the significant structures theory could satisfy this postulate. 

The discussion of potential energy surfaces thus far has implicitly assumed that gas-phase reactions are in focus. For condensed-phase reaction dynamics, where thermal fluctuations have a significant and intrinsic role, the situation is much more unsettled. The reader is referred to the list of challenges to condensed-phase electronic structure theory recently made by Truhlar, who asks if condensed-phase electronic structure may be "... not only waiting for its Hylleraas, but even waiting for its Schrodinger [112] The development of liquid-phase dynamics will surely continue to be an intense area of research through the foreseeable future. 

Another attempt to understand glass transition phenomenon from the theory of viscosity was made by Eyring and co-workers (1962, 1970). In their significant structures approach, the total partition function of the liquid was expressed as a product of solid-like and gas-like contributions. Then the viscosity is obtained from the activated complex theory after ignoring the contribution from gas-like part to viscosity. The final working expression for the viscosity of a system of rigid spheres was obtained as. 

His endless energy and glowing personality have carried worldwide his scientific genius to perceive and formulate the most reasonable and simple physical models with which to interpret important characteristics of complex systems and processes. The theory of absolute reaction rates and the significant structure model of liquids are classic examples. 

Marchi and Eyring have developed a partition function based on significant liquid structure theory proposed by Eyring et al. They assumed two solid-like species, a nonrotating hydrogen-bonded species and a rotating monomer. They further assumed that the monomer is able to rotate in the... 

Shredding plastic waste 1117,1138,1371 Significant Liquid Structures theory 129... 

Molecular dynamics simulations are a computational model of a collection of molecules that interact with one another under a specified set of conditions (temperature, pressure, etc.). While electronic structure theory calculations typically only involve one or a few molecules, molecular dynamics simulations can involve hundreds or thousands of molecules all at once. The purpose of molecular dynamics simulations is typically to investigate how molecules interact and react while surrounded by a collection of other molecules. While the energies of individual molecules can be investigated by electronic structure theory, a molecular dynamics simulation allows theoretical chemists to also study how molecules are influenced by their surroundings. These effects can be especially important in liquids, where solvent molecules can have a significant impact on reactivity. 

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