(a) Experiment (see Figure 3) versus theory. α1(0)=C[N4M/NM] and α1(∞)=C[NCu/NM] where NM is the total number of metallic Cu sites, N4M is the number of Cu atoms inside the non-overlapping 4-Cu-site plaquettes, and NCu is the total number of planar Cu sites. The low and high temperature linear T scattering rates arise from phonons and are given by 1/τ(0)~N4MT and 1/τ(∞)~NCuT, respectively. Dividing by the total number of charge carriers, NM, leads to α1(0) and α1(∞). For C=0.904 micro-ohm-cm/K, the RMS and maximum absolute errors are 0.017 and 0.17 micro-ohm-cm/K, respectively. There is exactly one adjustable parameter, C
(b) plot of the ratio α1(0)/α1(∞). C cancels out here, so there are zero adjustable parameters. For doping x < 0.187, N4M=NM because there are no overlapping plaquettes. Hence, α1(0)=C. The start of plaquette overlap at x=0.187 (vertical dashed line) leads to the sharp discontinuity in α1(0) there. Since NM→ NCu with increasing doping, α1(∞) at high doping tends to the same constant C, as observed.
(a) and (b) are the main results of the paper.