Iterative estimation of total π-electron energy

摘要

In this work, the lower and upper bounds for total π-electron energy (E) was studied. A method is presented, by means of which, starting with a lower bound E_L and an upper bound E_U for E, a sequence of auxiliary quantities E_0, E_1, E_2, ... is computed, such that E_0 = E_L, E_0 < E_1 < E_2 < ..., and E_∞ = E_U. Therefore, an integer k exists, such that E_k ≤ E < E_(k+1). If the estimates E_L and E_U are of the McClelland type, then k is called the McClelland number. For almost all benzenoid hydrocarbons, k = 3.