public void addCoords(Point3d[] iAtoms, Point3d[] jAtoms) {
		addCoords(iAtoms, null, jAtoms, null);
	}
public void addCoords ( Point3d [ ] iAtoms , Point3d [ ] jAtoms ) { addCoords ( iAtoms , null , jAtoms , null ) ; }
Adds the i and j coordinates and fills the grid. Their bounds will be computed.
Subsequent call to {@link #getIndicesContacts()} will produce the
contacts, i.e. the set of points within distance cutoff.

Subsequent calls to method {@link #getAtomContacts()} will produce a NullPointerException
since this only adds coordinates and no atom information.
@param iAtoms
@param jAtoms