Efficient method for calculating the resonance energy expression of benzenoid hydrocarbons based on the enumeration of conjugated circuits

To reduce the calculating time for the summations over linearly independent and minimal conjugated circuits of benzenoid hydrocarbons (BHs), an approx imate method is proposed that counts only the numbers of the first four cla sses of conjugated circuits R-1, R-2, R-3, and R-4, respectively. By repres entation of BHs as custom-made "ring-block chains" and use of the technique s of Database and visual computing, an application software is realized tha t is much faster and more powerful than the old one based on an enumeration technique.