code: public void populateMaps(){
  		this.elementName2Element = new HashMap<String, Element>();
  		this.isotopeName2Isotope = new HashMap<String, Isotope>();
  		if(this.element != null){
  			for(Element e:this.element){
  				this.elementName2Element.put(e.getName(), e);
  				if(e.getIsotopes() != null){
  					for(Isotope i:e.getIsotopes()){
  						this.isotopeName2Isotope.put(i.getName(), i);
  					}
  				}
  			}
  		}
  	}
docs: Populate the Maps for quick retrieval