I've been asked to shed some light on Huckel Theory for some workers here at U. Queensland. It's been a while since I seriously thought about Huckel theory, however. I'm doing some reviewing. I remember during my graduate school days hearing my advisor telling me sagely that the Huckel hamiltonian was based purely on the kinetic energy. This seems to make sense, since the theory is definitely 'nodal' . However, I'm having trouble connecting my intuitive understanding of how H is mostly KE in this theory with the math itself. Does anyone know any references that I can read over that will make this clearer?