Mehmet OrhanDepartment of Mechanical Engineering, Pamukkale University, TR-20070, Turkey. E-mail: morhan@pau.edu.trReceived December 11, 2013, Accepted January 24, 2014Use of acetonitrile in electrolytes promotes better operation of supercapacitors. Recent efforts show thatelectrolytes containing acetonitrile can also function in a wide range of operating temperatures. Therefore, thispaper addresses the dielectric relaxation processes, structure and dynamic properties of the bulk acetonitrile atvarious temperatures. Systems of acetonitrile were modeled using canonical ensemble and simulated byemploying Molecular Dynamics method. Results show that interactions among the molecules were correlatedwithin a cut-off radius while parallel and anti-parallel arrangements are observed beyond this radius atrelatively high and low temperatures respectively. Furthermore, effects of C-C-N and C-H bending modes weregreatly appreciated on the power spectral density of time rate change of dipole-dipole correlations whereasfrequency shifts were observed on all modes at the lowest temperature under consideration. Linear variationswith temperature were depicted for reorientation times and self-diffusion coefficients. Shear viscosity was alsocomputed with a good accuracy within a certain range of the temperature as well. Key Words : Acetonitrile, Molecular dynamics, Dielectric relaxation, Transport properties, EnergyIntroductionAcetonitrile (ACN) is an aprotic and polar solvent whichis widely used in chemical industry. Supercapacitors whichare also known as Electrochemical Double Layer Capacitors(EDLCs) are one of the technological applications in whichthe ACN is employed as a solvent in electrolytes due to itslow viscosity, good conductivity and permittivity despite itsvery low flash point (6