Hydrogen bonding investigation in 1-ethyl-3-methylimidazolium based ionic liquids from density functional theory and atoms-in-molecules methods

► Three types of hydrogen bond were determined for these ionic liquids. ► The interaction energy was a function of the number of hydrogen bonds. ► The distance dependence of electron density is an exponential decaying function. ► The intermolecular potential dependency has the polynomial inverse third order form.