code: public double calculateBondPolarizability(IAtomContainer atomContainer, IBond bond) {
          double polarizabilitiy = 0;
          IAtomContainer acH = atomContainer.getBuilder().newInstance(IAtomContainer.class, atomContainer);
          addExplicitHydrogens(acH);
          if (bond.getAtomCount() == 2) {
              polarizabilitiy += getKJPolarizabilityFactor(acH, bond.getBegin());
              polarizabilitiy += getKJPolarizabilityFactor(acH, bond.getEnd());
          }
          return (polarizabilitiy / 2);
      }
docs: calculate bond polarizability.
  
  @param  atomContainer    AtomContainer
  @param  bond  Bond bond for which the polarizabilitiy should be calculated
  @return       polarizabilitiy