void calcBfactorRange(BitSet bs) {
		if (!hasBfactorRange) {
			bfactor100Lo = Integer.MAX_VALUE;
			bfactor100Hi = Integer.MIN_VALUE;
			for (int i = atomCount; --i > 0;)
				if (bs == null || bs.get(i)) {
					int bf = atoms[i].getBfactor100();
					if (bf < bfactor100Lo)
						bfactor100Lo = bf;
					else if (bf > bfactor100Hi)
						bfactor100Hi = bf;
				}
			hasBfactorRange = true;
		}
	}