Correlation consistent composite approach

Oyedepo, G. A. Mlson, A. K. Multireference correlation consistent composite approach [MR-ccCA] toward accurate prediction of the energetics of excited and transition state chemistry, J. Phys. Chem. A 2010,114, 8806-8816. 

The Correlation Consistent Composite Approach (ccCA) Efficient and Pan-Periodic Kinetics and Thermodynamics... 

Abstract The correlation consistent Composite Approach (ccCA) methodology is the most accurate MP2-based model chemistry developed to date and contains no optimized empirically based parameters. As the method has continued to evolve and found new areas of application, we provide in this chapter a historical context of the developments and discoveries, an overview of variations of the ccCA model chemistry, and some discourse on future research thrusts. The success of ccCA for chemical applications is reviewed. 

This review will briefly compare and contrast current popular model chemistries in order to describe the motivation for the correlation consistent Composite Approach (ccCA). Initial calibration studies using the Gn training sets and initial comparisons to Gn methods will highlight chemical systems for which ccCA is a reliable and preferable model chemistry. Accomphshments and current development of ccCA will be discussed. 

The correlation-consistent composite approach (ccCA) is based in part on the G3B method, but uses Dunning correlation-consistent basis sets instead of Pople basis sets, does extrapolations to the CBS limit, replaces the QCISD(T) calculation with a CCSD(T) calculation, includes a relativistic correction, and contains no empirical parameters [N. J. DeYonker et al., J. Chem. Phys., 125, 104111 (2006) Mol. Phys., 107,... 

DeYonker, N. J., Cimdari, T. R., Wilson, A. K. (2006). The correlation consistent composite approach ccCA An alternative to the Gaussian-n methods. J Chem Phys 124,114104. 

A review is presented of techniques for the correlation and prediction of vapor-liquid equilibrium data in systems consisting of two volatile components and a salt dissolved in the liquid phase, and for the testing of such data for thermodynamic consistency. The complex interactions comprising salt effect in systems which in effect consist of a concentrated electrolyte in a mixed solvent composed of two liquid components, one or both of which may be polar, are discussed. The difficulties inherent in their characterization and quantitative treatment are described. Attempts to correlate, predict, and test data for thermodynamic consistency in such systems are reviewed under the following headings correlation at fixed liquid composition, extension to entire liquid composition range, prediction from pure-component properties, use of correlations based on the Gibbs-Duhem equation, and the recent special binary approach. 

A more selective approach consists in trying to influence the kinetics of formation of at least one network in this case, the two networks are formed more or less simultaneously, and the resulting morphology and properties can be expected to vary to some extent without changing the overall composition. The same system as previously studied, PUR/PAc, has been utilized in order to prepare a series of in situ simultaneous IPNs (SIM IPNs), by acting essentially on two synthesis parameters the temperature of the reaction medium and the amount of the polyurethane catalyst. Note that the term simultaneous refers to the onset of the reactions and not necessarily to the process. The kinetics of the two reactions are followed by Fourier transform infra-red (FTIR) spectroscopy as described earlier (7,8). In this contribution, the dynamic mechanical properties, especially the loss tangent behavior, have been examined with the aim to correlate the preceding synthesis parameters to the shape and temperature of the transitions of the IPNs. 

Data mining is a term used for a group of techniques used in finding useful patterns in the datasets. This approach consists in the analysis of huge data depositories in search of useful correlations between material properties and their composition. A simple example of data mining application in rubber design is given in Ref. ... 

Kinetics become anomalous and then Case II when the glass composition is approached and exceeded. Recent results on transport of carbon dioxide at high pressure are consistent with the correlations developed for organic liquids and vapors. 

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