“…Bell, H.C. Freeman, (Craven et al, 1977) given at 150 K for imidazole (abbreviation Im) and for the sample of ICB studied at room temperature together with the structure optimisation data (Holderna- Natkaniec,2006). On the basis of the X-ray and neutron diffraction data (Piecha et al, 2007;Zhang et al, 2005;Adams et al,2008;Levasseur et.al., 1991;Zhang et al, 2005;Valle&Ettorare ,1997) it can be concluded that imidazolium cation actually does not have the mm2 symmetry. However, the five-membered ring of imidazole skeleton is planar, but the hydrogen atoms lay more than 0.16 Å out-of-plane of the heterocyclic ring system, while both nitrogen atoms are linked to hydrogen atoms.…”