Monte Carlo-self-consistent field calculations

This type of layer structure, with a compact inner region and a dilute outer region, was also predicted by self-consistent field theory and by computer simulations. For instance, Monte Carlo simulations show that a dense layer (1-2 nm thick) is present close to the planar interface (74). This layer contained about 70% of the segments. Further out a region of mu eh lower density was found to extent about 10 nm into the aqueous phase. Similar results were obtained by self-consistent field calculations (75), which also showed that the most hydrophilic segments reside predominantly in the outer layer. 

Wang Q. Studying soft matter with soft potentials fast lattice Monte Carlo simulations and corresponding lattice self-consistent field calculations. Soft Matter 2009 5 4564. 

Starting from the normal mode approximation, one can introduce anharmonicity in different ways. Anharmonic perturbation theory [206] and local mode models [204] may be useful in some cases, where anharmonic effects are small or mostly diagonal. Vibrational self-consistent-field and configuration-interaction treatments [207, 208] can also be powerful and offer a hierarchy of approximation levels. Even more rigorous multidimensional treatments include variational calculations [209], diffusion quantum Monte Carlo, and time-dependent Hartree approaches [210]. 

Fu et al. [16] analyzed a set of 57 compounds previously used by Lombardo and other workers also. Their molecular geometries were optimized using the semiempirical self-consistent field molecular orbital calculation AMI method. Polar molecular surface areas and molecular volumes were calculated by the Monte Carlo method. The stepwise multiple regression analysis was used to obtain the correlation equations between the log BB values of the training set compounds and their structural parameters. The following model was generated after removing one outlier (Eq. 50) ... 

The development of adsorption theory provides the explanation of the macromolecule behavior in the adsorption layer and provides the basis of arguments on the experimental results. A few theoretical models, describing the adsorbed macromolecule, are widely used now. Self-consistent field theory or mean field approach is used to calculate the respective distribution of trains, loops, and tails of flexible macromolecule in the adsorption layer [22-26]. It allows one to find the segment density distribution in the adsorption layer and to calculate the adsorption isotherms and average thickness of the adsorption layer. Scaling theory [27-29] is used to explain the influence of the macromolecule concentration in the adsorption layer on the segment density profile and its thickness. Renormalization group theory [30-33] is used to describe the excluded volume effects in polymer chains terminally attached to the surface. The Monte Carlo method has been used for the calculation of the density profile in the adsorption layer [33-35]. 

An novel approach is the combination between self-consistent field theoretical approaches and Monte Carlo simulations called theoretically informed coarse grain simulations [120]. It was developed in the field of block copolymers and could easily be extended to PE based copolymers and also thermodynamic calculations [120]. 

Electron transport simulation is performed using earlier developed ensemble Monte Carlo algorithms and procedures, which include self-consistent solution of Poisson and Boltzmann equations [3,4]. In general, in both types of MOSFETs the normal component of electric field at Si/Si02 interface in a certain jc-point of the channel may be calculated using the following expression... 

Very recent Monte Carlo simulations and self consistent mean field calculations [223] have shown that wetting properties might be reflected in the phase diagram of a blend confined between symmetric selective surfaces Close to Tw a convex curvature is exhibited by the phase diagram on the side poor in preferentially adsorbed polymer. Also the temperature dependence of Ap changes around the wetting point Tsv. 

The study of solvatochromic shifts is of great importance and has received enormous theoretical attention in recent years. Progress has been achieved in the use of the self-consistent reaction field and cavity models. These advances have also shown several limitations. It is thus of great interest to have alternative procedures to calculate solvent effects. In this respect the use of Monte Carlo/Molecular Dynamics simulations has been growing. In this paper we suggest a procedure to allow a full quantum mechanical calculation of the solute-solvent system. The basic idea is to treat the solute, the solvent and its interaction by quantum mechanics. First a Monte Carlo simulation is performed to characterize the liquid structure. These structures are then used in the quantum mechanical calculation. As a liquid has not one but a great number of structures equally possible within a... 

Many standard search methods have been used in side-chain conformation prediction, including Monte Carlo simulation [176-178], simulated annealing [179], self-consistent mean field calculations [154, 173, 180], and neural networks [170]. Self-consistent mean field calculations represent each side chain as a set of conformations, each with its own probability. Each rotamer of each side chain has a certain probability, p(n). The total energy is a weighted sum of the interactions with the backbone and interactions of side chains with each other ... 

Colominas et al. [143] published a very detailed study on the dimerization of formic and acetic acids in the gas phase and in aqueous and chloroform solutions. By using quantum mechanical self-consistent reaction field and Monte Carlo calculations, they showed that the dimerization is favored in the gas phase and in a chloroform solution (1M) basically due to double hydrogen-bonded interaction between the monomers. In aqueous solution, the dimerization does not seem to occur due to the competitive solute-solvent intermolecular interactions. The computed dimerization energies are shown in Table VII. 15... 

FIG. 3 C33 axial modulus of polyethylene obtained using different force fields and computational methods. All calculations are classical. Open symbols are from optimizations (circles, triangles, and diamond are self-consistent QHA lattice dynamics, all others are plotted at temperature of experimental lattice parameters potential energy minimizations are plotted at OK). Filled symbols are Monte Carlo (circles) or molecular dynamics (diamond, triangles). Force field of Ref. 55 open and filled circles (from Ref. 46) force field of Ref. 30 open (from Ref. 33) and filled (from Ref. 68) triangles pcff force field of Biosym/MSI open and filled diamonds (from Ref. 66) x (from Ref. 42) -I- (from Ref. 43) open inverted triangle (from Ref. 44) open square (from Ref. 29). Curves are drawn as guides to the eye. 

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