Abstract
On the basis of the general rules to get propagators under the Rückel approximation, practical calculation methods for the quantum chemical quantities of the topological reference systems are proposed. Where a topological reference system is replaced by a corresponding tree conjugated system. Quantum chemical quantities of a topological reference system are obtained by calculating the Hückel molecular orbitals of a corresponding tree conjugated system. In order to get a corresponding tree conjugated system of a topological reference system, simple diagrammatical methods are proposed. For exercises, several quantum chemical quantities for some [n]-Hückel annulene, n= 3 to 10, are calculated.
