Syntax

RESTraints

DIHEdral { <restraints-dihedral-statement> } END is invoked from the main level of X-PLOR. Invocation automatically turns on the CDIH energy flag (Section 4.5).

<restraints-dihedral-statement>:==

ASSIgn

<selection> <selection> <selection> <selection>
<real> <real> <real> <integer> adds a new dihedral angle to the restraints-dihedral database. The four selections have to be unique; i.e., each selection must select exactly one atom. The selections determine the four atoms that specify the dihedral angle. The first <real> number specifies the energy constant (C) in kcal mole rad, the second <real> number specifies the angle in degrees to which the dihedral angle is restrained (), the third <real> number specifies the range around the restrained angle (), and the <integer> number specifies the exponent (ed).

NASSign=<integer>

is a required parameter that specifies the maximum expected number of assignments. It has to be greater than or equal to the actual number (default: 400).

RESEt

erases the restraints-dihedral database.

SCALe

specifies the overall weight factor S.