Semiempirical method for calculating structure and band gap of semiconducting polymers

A semiempirical method that yields accurate band gaps and atomic positions in sp2-hybridized, organic, semiconducting polymers has been obtained. This method is a tight-binding calculation where most of the parameters are determined via an ab initio local density approximation method leaving only π–π interactions to be adjusted empirically. Once fitted for one or two systems, the method can be applied to other similar systems without further adjustment. Accurate results have been demonstrated for a number of semiconducting polymers that contain C, S, N, and H.