The on-site (HOMO) energy values of the monomer fragments (ϵ 𝑘 ) are calculated within the LMOM method. Since we assume that the polymer chains remain in a glassy state, as previously mentioned in the Introduction, the overall chain conformation i.e., the sequence of quasi-frozen dihedral angles between neighboring monomers ({𝜃 𝑘,𝑓𝑟𝑜𝑧𝑒𝑛 }) are determined employing the torsional potential parameters of the corresponding monomer pairs; for each monomer pair (𝑘, 𝑘 + 1), 𝜃 𝑘,𝑓𝑟𝑜𝑧𝑒𝑛 is chosen from the Boltzmann distribution at 300K (details are provided in SI). In effect, our method of generating dimer conformations automatically accounts for the preference between syn-and anti-conformations and no further geometry relaxation is introduced after the chain conformation is generated.