code: public double calculateKJMeanMolecularPolarizability(IAtomContainer atomContainer) {
          double polarizabilitiy = 0;
          IAtomContainer acH = atomContainer.getBuilder().newInstance(IAtomContainer.class, atomContainer);
          addExplicitHydrogens(acH);
          for (int i = 0; i < acH.getAtomCount(); i++) {
              polarizabilitiy += getKJPolarizabilityFactor(acH, acH.getAtom(i));
          }
          return polarizabilitiy;
      }
docs: calculates the mean molecular polarizability as described in paper of Kang and Jhorn.
  
  @param  atomContainer  AtomContainer
  @return     polarizabilitiy