A Class of Lower Bounds for Total 7t-Electron Energy of Alternant Conjugated Hydrocarbons

For alternant hydrocarbons whose molecular graphs possess n vertices and m edges Tiirker recently put forward a lower bound for total n-electron energy (E), namely (1/2) (2 m n)1/2 :$ E (*). The original proof of (*) contains an error. We propose an alternative method for proving (*), which applies to all molecular graphs, except perhaps to some containing very many fourmembered cycles. As a byproduct, a class of novellower bounds for E is obtained.