Watch monitors interatomic distances. By default, it checks for distances less than the sum of the van der Waals (VDW) radii of two atoms. Atoms in the atom-spec are checked against all other atoms to whom their distance can potentially vary (atoms in other models or atoms in the same model across from active bond rotations). Close contacts are displayed as yellow dotted lines, in the same manner as distance monitors. One can specify a fixed distance by using the distance option to watchopt, where distance is in angstroms. If distance is not used, or a distance of zero is specified, the default VDW radii are used for comparison. Only distances that potentially vary are checked, i.e., atoms that are fixed relative to each other are not checked.
~Watch terminates such monitoring.
See also: distance