Couplings make

Parameters

first=string (required)

second=string (required)

value=real

(default: 1.0)

tolerance=real

(default: 1.0)

weight=real

(default: 1.0)

karpluscurve=string

(default: none)

Description

Add new scalar coupling constant restraints. Scalar coupling constant restraints are added between atoms selected by the first and second atom selections, respectively. The scalar coupling constant value, its tolerance, relative weight, and Karplus curve parameters are set as given by the value, tolerance, weight, and karpluscurve parameters.

The command can also be used to simulate scalar coupling constant restraints on the basis of a given structure: If the value parameter is not given, then the scalar coupling constant value of the new restraints will be to the average value obtained from the selected conformers using the given Karplus curve.

Karplus curves must be specified in the form A+B*cos(d)+C*cos(d)**2, where A, B and C are real numbers, and d denotes the value of the torsion angle formed by the two scalar coupled atoms.