Torsional angle distribution

Figure 2-108. Derivation of a syrMbolic potential energy function from the torsion angle distribution of a torsion fragment.

Fig. 7.6 Torsion angle distribution for ortbo-substituted phenol ethers (bars) and the derived potential energy (closed line).

GoldScore ChemScore FHit Rag. MC,n, .lnB Torsion Angle Distributions... 

The results for the C71 chains also show that the performance of off-lattice simulations must be assessed by looking at all possible aspects of the simulation. Often used criteria, such as internal energy variation, torsional angle distribution function, and radial distribution function [38, 39,45] do not by themselves provide reliable performance indicators. 

The chain molecule solution will be characterized by a set of rotational isomeric states. After the initial thermalization, this set will still be in a nonequilibrium state due to the overall shear deformation. For the internal torsional angle distribution to relax to equilibrium, it is necessary for the solution liquid structure to relax and the solvent molecule distribution to reach equilibrium. In a concentrated polymer solution, these processes are highly coupled. Rotational isomeric state changes depend on both internal potentials and the local viscosity and are often in the nanosecond range, well above the glass transition for the solution. Total stress relaxation cannot occur any faster than the chains can change their local rotational isomeric states. 

Figure 26.5 illustrates the torsion angles distribution in vacuum and in water of the optimized dimers, D(CH3), and monomers, M(OH). The data prove that... 

Comparing Figs. 26.5 and 26.9 one easily sees the similarity between the MD statistics and the quantum mechanical calculations. In both approaches the anti-orientation is the most populated with sizeable presence of awc/id-bends. The reproduction of the torsion angle distribution by the MD simulation supports the applicability of the derived parameters. 

PCMs such as n-nanodecane, n-eicosane, n-heneicosane, and n-docosane. The results of this study showed that the thickness of the shell material had a great influence on the self-diffusion coefficient, radial distribution function, end-to-end distance, and bond torsion angles distribution of the nano-encapsulated PCM. The authors also noted that the thicker the shell is, the more restricted are the torsion and the extension of the core material molecule chains, especially those that are close to the shell. The mass diffusion and the storage of thermal energy are enhanced when the thickness of the shell decreased, but the capsule is prone to break if the shell is too thin. In the nano-encapsulated PCM design, the influence of the shell thickness must be taken in account [20,21]. 

Exemplified bond and torsion angle distributions of seguence/l4fi22l452l262l3622l at different temperatures. The distributions ofthe torsion angles are reflection-symmetric and therefore only the positive intervals are shown. From [47],... 

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