It is now known that these extrapolations deviate from linearity at large values of n. This is due to the saturation effect, or the maximum number of repeat units that can contribute to π delocalization along the polymer backbone. The saturation effect depends strongly on the conformation of the polymer, which can be adversely affected by monomer substitutions, solvent effects, and backbone rigidity. Many models have been developed to account for saturation effects , and terms such as the effective conjugation length and the maximum conductive chain length have been established to describe and quantify this phenomenon. When utilizing the simple 1/n extrapolation method to determine the Eg of a polymer from its constituent oligomers, the predicted infinite polymer HOMO/LUMO gap tends to underestimate the experimental values.