The Martini CG force field (FF) is a widely used CG model, in particular for MD lipids. The naming convention adopted for the two-tailed IL models consists of the two-letter combination for the tails (typically used for phospholipids), followed by a two-letter combination for the head/linker region. For the head, the first letter remains the same across protonation states, while the second letter changes to "P" for the charged protonated state (see Figure ).