Comparison of the average degree of ionisation of carbon plasmas as a function of mass density at a plasma temperature of 100 eV, predicted by various theoretical methods. Shown are results from DFTMD simulation (black dotted line) (Bethkenhagen et al. 2020); BU calculations (Röpke et al. 2019) incorporating two different IPD models – SP (long black-dashed line) and EK (dotted, short-dashed black line) – and including the PB effects (short-dashed black line); PURGATORIO (dotted, long-dashed black line) (Sterne et al. 2007); OPAL (dot-dot-dashed black line) (Rogers et al. 1996); ATOMIC (dot-dashed-dashed black line) (Hakel et al. 2006); TF and TFD models (Clerouin et al. 2022); Qp and Qs ionisation (Clerouin et al. 2022); QAAM (Faussurier et al. 2021); PMC05 calculation at a temperature of 10⁶ K (Potekhin et al. 2005); and the NPA model (Dharma-wardana 2021).