For each polymer, we sampled 250 chains, which are all statistically independent according to the block averaging analysis performed on SCP chain lengths, as shown and discussed in SI, section S2.3. The electronic structure (orbital energies and localization) for each chain was computed taking into account their electrostatic environment (included via the point charges of all repeat units which have at least one atom within 2 nm distance from any atom in the polymer backbone) from both "melt" and "soup" simulation trajectories (see Figure ). These calculations are sped up with negligible loss of accuracy by using the smaller 3-21G* basis set and the same functional (B3LYP) used to derive the force field parameters. The DOS of each sample was calculated (see the QC calculation details in ref ) and averaged over 250 chains. It should be noted that in p-type organic semiconductors (including all the SCPs investigated in this paper), the shape of the DOS, particularly the distribution of states at the valence band edge, is closely tied to electronic disorder and hence charge mobility . Quantifying this, for example, via the slope of the valence band tail or by the charge carrier localisation length (LL) at the valence band edge provides a valuable link between electronic structure calculation and experimentally measurable quantities, e.g., mobility.