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Dihedral Angle Restraints
The following example shows how to set up torsion angle
restraints. Coupling constant measurements
provide a means to obtain information about certain
dihedral angles, albeit with low precision. The low
precision makes it necessary to employ rather large error
ranges.
restraints dihedral reset assign (resid 1 and name c) (resid 2 and name ca) (resid 2 and name n) (resid 2 and name c) 1 -120.0 40.0 2 {* 9 Hz *} assign (resid 2 and name c) (resid 3 and name ca) (resid 3 and name n) (resid 3 and name c) 1 -120.0 50.0 2 {* 8 Hz *} endThe four selections of each assign statement specify the particular dihedral angle. The first number after the selections specifies the energy constant () in kcal mole rad, the second number specifies degrees to which the dihedral angle is restrained (), the third number specifies the range around the restrained angle (), and the last number specifies the exponent of the restraining function. (Refer to Section 7.2 for more information.)
Xplor-NIH 2024-09-13