code: public static MoleculeProperty getMoleculeProperties(HELM2Notation helm2notation) throws BuilderMoleculeException, CTKException, ExtinctionCoefficientException, ChemistryException {
      MoleculeProperty result = new MoleculeProperty();
      /* First build HELM molecule */
      List<AbstractMolecule> molecules = buildMolecule(helm2notation);
      /* calculate molecular formula */
      result.setMolecularFormula(calculateMolecularFormula(molecules));
      /* calculate molecular weight */
      result.setMolecularWeight(calculateMolecularWeight(molecules));
      /* calculate exact mass */
      result.setExactMass(calculateExactMass(molecules));
      /* add Extinction Coefficient calculation to it */
      result.setExtinctionCoefficient(ExtinctionCoefficient.getInstance().calculate(helm2notation));
  
      return result;
    }
docs: method to get all molecule properties for one HELM2Notation
  
  @param helm2notation given HELM2 object
  @return List of molecule properties: molecular formula, molecular weight,
  exact mass, extinction coefficient
  @throws BuilderMoleculeException if helm molecule can not be built
  @throws CTKException general ChemToolKit exception passed to HELMToolKit
  @throws ExtinctionCoefficientException if the extinction coefficient can not be calculated
  @throws ChemistryException if the Chemistry Engine can not be initialized