where angular brackets denote the ensemble average, i.e., average over all sampled configurations of all lipids in a simulation, and θ is the angle between the C-H bond and the membrane normal. As in previous NMRlipids publications, the order parameters were first calculated separately for each lipid and the standard error of the mean over different lipids was used as the error estimate . However, order parameters for simulations with τ rel > 1 may be influenced by the starting structure and thereby their error bars may be underestimated. The script that calculates C-H bond order parameters from all simulations in the NMRlipids Databank is available at /Scripts/AnalyzeDatabank/calcOrderParameters.py in the NMRlipids Databank repository. The resulting order parameters are stored for all simulations in files named [lipid_name]OrderParameters.json at folders in /Data/Simulations in the NMRlipids Databank repository.