Description

This error may occur during a geometry optimization or gradient minimization and usually indicates that a dihedral angle is about to become undefined. This happens when the three atoms used to define a fourth’s dihedral approach a straight line. The ways to circumvent this error are to redefine the connectivity of the molecule, use Cartesian coordinates, or use one or more dummy atoms. Note that if the three atoms are in an exactly straight line, this message will not be triggered.