To further evaluate the performance of the Ca 2+ models used in this study, we compared our simulation results with experimental data. The C±H bond order parameters obtained from NMR experiments serve as valuable metrics for validating the consistency of lipid structures in MD simulations with experimental data. These measures are particularly relevant as they are associated with key bilayer properties such as area per lipid, thickness, and the conformational variability of individual lipids. Previous MD studies used these metrics to evaluate the Ca 2+ model with electronic continuum correction (ECC). Here, we also analyzed the changes of the headgroup C±H order parameters in our simulations with increasing CaCl 2 concentrations and compared with experimental values. As can be seen, the change tendencies of the β, α, g 3 order parameters were consistent with the experimental results when both the Cam and Cal models were used (Figs. and). However, it is also noticeable that most of the simulation results with the Cam model showed better consistency with the experimental data than the Cal model, except for the β order parameter in the pure POPC bilayer (Fig. ). This indicates that our Cam model overall performed better than the default Cal model in simulating the lipid bilayer systems.