The elucidation of molecular interactions within the Ionic Liquid 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM]PF₆ is the subject of the present report. Infrared and Raman spectra were obtained for the ionic liquid and the molecular geometry, vibrational frequencies and bonding features in the ground state were calculated using DFT/B3LYP method with 6-311G(d, p) basis set. To study the significant bonds in the imidazolium ring, Natural Bond Orbital (NBO) analysis was also carried out at the HF/6-311+G(d, p) level. The calculated energy gap between Homo and Lumo orbital’s was of 276.52 kcal/mol. Charge transfer bands of the [BMIM]PF₆ ionic pair are discussed.