code: @Override
      public DescriptorValue calculate(IAtomContainer container) {
          //System.out.println("FragmentComplexityDescriptor");
          int a = 0;
          double h = 0;
          for (int i = 0; i < container.getAtomCount(); i++) {
              if (!container.getAtom(i).getSymbol().equals("H")) {
                  a++;
              }
              if (!container.getAtom(i).getSymbol().equals("H") && !container.getAtom(i).getSymbol().equals("C")) {
                  h++;
              }
          }
          int b = container.getBondCount() + AtomContainerManipulator.getImplicitHydrogenCount(container);
          double c = Math.abs(b * b - a * a + a) + (h / 100);
          return new DescriptorValue(getSpecification(), getParameterNames(), getParameters(), new DoubleResult(c),
                  getDescriptorNames());
      }
docs: Calculate the complexity in the supplied {@link IAtomContainer}.
  
  @param  container  The {@link IAtomContainer} for which this descriptor is to be calculated
  @return                   the complexity
  @see #setParameters