BitSet setConformation(int modelIndex, int conformationIndex) {
		BitSet bs = new BitSet();
		String altLocs = getAltLocListInModel(modelIndex);
		if (altLocs.length() > 0) {
			BitSet bsConformation = getModelAtomBitSet(modelIndex);
			if (conformationIndex >= 0)
				for (int c = getAltLocCountInModel(modelIndex); --c >= 0;)
					if (c != conformationIndex)
						bsConformation.andNot(getSpecAlternate(altLocs.substring(c, c + 1)));
			if (bsConformation.length() > 0) {
				setConformation(modelIndex, bsConformation);
				bs.or(bsConformation);
			}
		}
		return bs;
	}