Controversies in lipid membrane simulations Dozens of force fields and combinations thereof are available for simulating lipid membranes and their interactions with other molecules, such as proteins, drugs, and ions. Even though the quality of force fields has been widely evaluated against experimental data during parameterization and in separate comparison studies, defining unambiguously their overall quality still remains unclear, and several controversial results are reported for each in the literature, as exemplified in Table . Because universal quality measures for membrane simulations are not available, it is difficult to estimate, even for an expert, the reliability of a certain MD simulation result or to select the best force field for a specific application.