A CLASS OF LOWER BOUNDS FOR TOTAL PI-ELECTRON ENERGY OF ALTERNANT CONJUGATED HYDROCARBONS

For alternant hydrocarbons whose molecular graphs possess n vertices a nd m edges Turker recently put forward a lower bound for total pi-elec tron energy (E), namely (1/2) (2 m n)(1/2) less than or equal to E () . The original proof of () contains an error. We propose an alternati ve method for proving (), which applies to all molecular graphs, exce pt perhaps to some containing very many four-membered cycles. As a byp roduct, a class of novel lower bounds for E is obtained.