This code can be used to generate a Pisarenko (carrier concentration [carriers/cm^3] vs Seebeck coefficient [uV/K]) plot using a two band Kane model. Lines 25 - 37 will need to edited for your material. The E_gap, K, etc values are currently for SnTe. Coded using math from: Wiendlocha, Candolfi et al, 2021, Residual resistivity as an independent indicator of resonant levels in semiconductors and Zhang, Ren 2013 PNAS, High thermoelectric performance by resonant dopant indium in nanostructured SnTe 9