void removeGhostABonds() {
		if (aBonds.isEmpty())
			return;
		ABond ab;
		synchronized (aBonds) {
			for (Iterator i = aBonds.iterator(); i.hasNext();) {
				ab = (ABond) i.next();
				if (getRBond(ab.atom1, ab.atom3) == null || getRBond(ab.atom2, ab.atom3) == null) {
					i.remove();
				}
			}
		}
	}