Torsion angles variation

Fig. 4.S Variation in torsional energy (AMBER force field) with O-C-C-0 torsion angle (to) for OCH -CHjO fragment. The minimum energy conformations arise for to = 60° and 300°.

Fig. 5.1 Variation in the energy of pentane with the two torsion angles indicated and represented as a contour diagram and isometric plot. Only the lowest-energy regions are shown.

Fig. 7.15 The variation in torsion angles can be effectively represented as a series of dials, where the time corresponds to the distance from the centre of the dial. Data from a molecular dynamics simulation of an intermolecular complex between the enzyme dihydrofolate reductase and a triazine inhibitor [Leach and Klein 1995].

Through measurement of the lateral-voltage variation of the position detectors, the torsional angle Oj of the cantilever can be given by... 

Then, the corresponding relationship between lateral voltage of the four-quadrant position detectors (F/) and the torsional angle of the cantilever ( di). Thus we can obtain the variation of torsional angle 0i through reading the variation of lateral voltage (F ) from the front panel. 

Despite the strong interest in the correlation between torsion angle and transport properties, suitable model compounds enabling the systematic variation of the torsion angle in biphenyl systems have not been realized so far, and the role of geometric and electric effects of the substituents is still being actively discussed [48, 72, 74, 271, 277]. 

Table 3.24. Torsionalflexing p/NfECI-EF, showing relaxed R c and Rqf bond lengths and (9 pNC and %cr valence angles with variation of the torsion angle (cf. Fig. 3.64) (0ipnc denotes the angle between the lone pair and ctnc NHOs at N)...

One result of the simulations was that the torsion angle q> between successive nucleosomes determines the properties of the structure to a great extent (as also predicted by the two-angle model). While a variation in the internucleosome interaction potential by a factor of four changes that simulated mass density by only about 5%, this quantity is very sensitive to variations in twist angle (see Fig. 6 in Ref. [50]). 

Figure 1. The variation of bond angles C5-05-C1 and 05-C1-01 with the torsion angle < ) for 2-methoxytetrahydropyran. The curves with squares (C5-05-C1) and triangles (05-C1-01) are for the axial form and the rhombuses (C5-05-C1) and stars (05-C1-01) are for the equatorial form. These curves were calculated with PCILO, with full optimization of geometry at each increment.

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