Möbius and hückel systems in the SCF and CI approximations

Over the last 15 years since the introduction of Möbius-Hückel theory, a number of varied questions has accumulated. The most interesting of these deals with the question of whether or not the Möbius-Hückel theory is valid in the SCF and SCF-CI approximation. This paper presents a treatmet which shows that the repulsion and exchange contributions are independent of the Möbius vs Hückel nature of the orbital array. Also it is shown that the one-electron terms are symmetry determined and derive from SCF coefficients. An analytical SCF-CI treatment if given. Several further unanswered questions are also considered.