• OPLS-AA
• DFTB
• DFT
• computational chemistry
• ionic liquids

Ionic liquids (IL) are a class of solvents that presents a melting point below 100 °C, additionally formed by at least one pair of a cation and an anion that present a high variety of application due to the interesting proprieties for many fields of research and industry. To study this group of compounds, the computational method is a powerful tool for the study and understanding of IL. In this work, we study the IL made with the imidazolium group as the cation and the Bromide and tungstate as anions. We use different computational methods and technics to determine the stability and the best conformation for this IL using the semi-empirical and classical methodology. This study observes that the IL made with the tungstate anion presents higher stability, better conformation, and lower energy when compared with the bromide anion because of the charge distribution and the anion size. Was also observed that the orientation of the imidazolium group also has a major influence on the stability of the compound.