The optimized geometrical structures of [EMI] + cation are shown in Figure . According to our results, the most stable geometry ω97X-D/6-311++G(3df,2dp) level of theory showed a nonplanar staggered with the dihedral angles N 7 -C 5 -N 8 -C 13 and C 9 -N 7 -C 5 -H 6 of 177.684° and 0.334° respectively (Table ). Our results show agreement with previously reported results .