Atom getSymmetryBaseAtom(int modelIndex, int site, int symop) {
		Frame.CellInfo[] c = cellInfos;
		if (c != null)
			for (int i = 0; i < atomCount; i++)
				if (atoms[i].modelIndex == modelIndex && atoms[i].atomSite == site && atoms[i].atomSymmetry.get(symop))
					return atoms[i];
		return null;
	}