To further test whether the structural disorder correlates with capacitance, a previously reported NMR simulation approach was applied to predict the correlation length associated with the size of 165 the ordered aromatic carbon domains (Fig. , see Methods) . This simulation approach accounts for the experimental pore size distribution and the strength of the ion-carbon interactions; the NMR chemical shifts are then modelled using model polyaromatic hydrocarbon fragments separated by distances governed by the pore size distribution (see Methods). These simulations support the idea that carbons with smaller calculated ordered domain sizes generally have higher 170 capacitances (Fig. ). X-ray pair distribution function (PDF) patterns of the studied carbons supported the findings from NMR spectroscopy (Fig. ). Comparing the X-ray PDF patterns of SC-1800 (small Δδ value, high capacitance) and PW-400 (large Δδ value, low capacitance), we find that the SC-1800 has a more rapid decay of the pairwise C-C correlations , consistent with the smaller domain sizes and/or more the disordered local structure of SC-1800. X-ray PDF results for the other carbons yielded similar results (fig. ), with a quantitative analysis of the decay rates lending additional support that structural disorder is correlated with capacitance. (fig. S17-S21, table ). Summarizing, we have found that more disordered carbons with smaller ordered domains have higher capacitances. 180 These findings may help to resolve the previous contradictory reports on the impact of carbon pore size on capacitance . A master plot of our measured Dd values including literature values for TiC-CDC materials is shown in Fig. . TiC-CDC-600 (i.e., a sample prepared at 600ºC) exhibits a large capacitance and a small Dd value, while TiC-CDC-1000 has a low capacitance and large Dd value. This is consistent with a more disordered structure for TiC-CDC-600, as is well known 185 from previous molecular simulation work and conductivity measurements that showed an increase in structural order as the synthesis temperature was increased. We therefore hypothesize that carbon disorder, rather than pore size, gave rise to previously reported "anomalous" increase in capacitance for samples prepared at low temperature (3). More generally it is possible that the impact of structural disorder has been overlooked in a range of studies on capacitance, and 190 it is clear that structural disorder should be controlled as far as possible in any study of pore size effects.