To determine how well the stepwise application of these statistical models perform, the infinite polymer molecular orbital energies were calculated using the functions generated by the OLS regressions along with 1) experimental monomer DFT energies only, 2) experimental monomer and dimer DFT energies, and 3) experimental dimer and tetramer DFT energies only. The mean absolute error for each case was computed by comparing these results to the polymer FMO energies. This process was performed for the polymer HOMO energy, the polymer LUMO energy, and the polymer Eg energy. The results of this analysis are summarized in Table . Note that the training set data was used to calculate the predicted polymer FMO energies in each case for ease of comparison. The actual magnitudes of the errors in Table are likely larger.