private BitSet getSpecNameOrNull(String name) {
		BitSet bs = null;
		name = name.toUpperCase();
		for (int i = atomCount; --i >= 0;)
			if (atoms[i].isGroup3OrNameMatch(name)) {
				if (bs == null)
					bs = new BitSet(i + 1);
				bs.set(i);
			}
		return bs;
	}