An effective hopping model for weakly interacting pi systems: Electronic structure of stacked polyaromatic hydrocarbons

Parameters for effective hopping integrals are extracted from ab initio Har tree-Fock calculations on model systems. These effective hoppings can be us ed to describe the attractive part of the interaction of loosely bonded pi -electron systems of various orientations, such as interchain hoppings in c onjugated polymers or those between two-dimensional graphitic sheets. (C) 2 001 John Wiley & Sons, Inc.