CVFF force fields

CFF91, CVFF - force fields used in molecular mechanics calculations CNDO - Complete Neglect of Differential Overlap DFT- Density Functional Theory DS - Dynamic Simulations MC - Monte Carlo Simulations MD - Molecular Dynamics MM - Molecular Mechanics... 

The TRIPOS, Chem-X, CHARMm, COSMIC, and CVFF force fields all use only the harmonic approximation, whereas in the DREIDING force field, angle bending is described by a harmonic cosine function where 0 and 0o in Eq. [6] are replaced by cos 0 and cos 0q, respectively, to avoid a zero slope as 0 approaches 180°. In the UFF force field, angle bending is described with a small Fourier expansion in 0 (Eq. [7]). This functional form was selected to better describe large-amplitude motions. 

Besides MM2 and MM3, MMFF93 and CFF91 employ a three-term Fourier expansion, whereas the TRIPOS, Chem-X, CHARMm, COSMIC, DREIDING, and CVFF force fields all use a simple single-term, torsional potential energy... 

Fig. 48. The geometries used in the simulations in the left column have been optimized with the CVFF force field whereas the right column relies on AMBER geometries. The overall agreement with experiment is comparable. The simulated AMBER spectra are somewhat smaller than their CVFF counterparts...

The presence of the CVFF force field in a graphical modeling package (Insightll, Discover) has facilitated its application to several classes of biomolecules including oligosaccharides, despite its lack of specific parameters for carbohydrates. ... 

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