Following the logic presented when constructing the models to predict dimer FMO energies, it was expected that similar relationships exists between the HOMO, LUMO, and Eg energies of the (AB)n co-oligomers, and the building blocks which compose them (i.e. "A" and "B" monomers, "AB" dimers, "ABAB" tetramers, etc.). It was also expected that the relative change in HOMO, LUMO, or Eg energy from dimer to tetramer would be a useful predictor for the extrapolated polymer FMO energies. OLS regression models were constructed by utilizing a minimal number of parameters to maximize the R 2 value while minimizing the p-values of each parameter. These models are summarized in Table . The tetramer and dimer models were constructed using the data from all 4095 compounds. The polymer models were constructed using only 60 of the 70 possible compounds, the other 10 compounds were used as a validation set. The mean absolute errors in Table were calculated by comparing the experimental results from the training set with the predicted values. The equation and summary of the OLS results for the tetramer and polymer models are given in Tables S8 -S13 of the supporting information.