code: public boolean validate(IMolecularFormula formula, double value) throws CDKException {
  
          double charge = 0.0;
  
          if (formula.getCharge() != CDKConstants.UNSET) charge = formula.getCharge();
  
          long iPart = (long) value;
          double fPart = value - iPart;
  
          if (fPart == 0.0 && charge == 0) return true;
          if (fPart != 0.0 && charge != 0)
              return true;
          else
              return false;
  
      }
docs: Validate the ion state. It takes into account that neutral, nonradical compounds
  always have an even-numbered pair-wiser arrangement of binding electrons signilizaded
  by an integer DBE value. Charged compounds due to soft ionzation techniques
  will give an odd number of binding electrons and a fractional DBE (X.05).
  
  @param formula   Parameter is the IMolecularFormula
  @param  value    The RDBE value
  @return          True, if corresponds with