Calculating Phase Diagrams of Polymer-Clay Mixtures by Combining Density Functional and Self-Consistent Field Theory

1999 ◽  
Vol 576 ◽  
Author(s):  
Anna C. Balazs ◽  
Chandralekha Singh ◽  
Valeriy V. Ginzburg
Keyword(s):  
Density Functional ◽  
Equilibrium Phase ◽  
Organic Modifiers ◽  
Functional Theory ◽  
Clay Particles ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory

ABSTRACTWe analyze the thermodynamics of polymer-clay mixtures within the framework of density functional theory (DFT). The interaction potential between clay particles is calculated using the self-consistent field (SCF) method and is strongly dependent on the length and density of grafted short-chain organic modifiers. By combining the DFT and SCF techniques, we determine the role of the grafted chains on the equilibrium phase behavior of the mixtures.

On the dissociation energy of Ti(OH2)+. An MCSCF, CCSD(T), and DFT study

1996 ◽  
Vol 74 (10) ◽  
pp. 1824-1829 ◽  
Author(s):  
A. Irigoras ◽  
J.M. Ugalde ◽  
X. Lopez ◽  
C. Sarasola
Keyword(s):  
Dissociation Energy ◽  
Density Functional ◽  
Basis Sets ◽  
Coupled Cluster ◽  
Functional Theory ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Self Consistent Field Theory ◽  
Effective Core Potentials

The dissociation energy of the Ti(OH2)+ ion–molecule complex was calculated by the multiconfigurational self-consistent field theory, coupled cluster theory, and two density functional theory based methods, using both all-electron basis sets and effective core potentials. The calculations show that approximate density functional theory gives results in better agreement with experiment than either the multiconfigurational self-consistent field theory or the coupled cluster theory, with both all-electron basis sets and effective core potentials. Nevertheless, the optimized geometries and harmonic vibration frequencies are very similar, irrespective of the level of theory used. The interconfigurational energy ordering of the two valence electronic configurations dn−1s and dn−2s2 of the 4F electronic state of the titanium cation were also calculated and are discussed. Key words: ab initio, dissociation energy, ion–molecule complex, effective core potentials, transition metals.

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