Comparison of CHARMM and OPLS-aa forcefield predictions for components in one model asphalt mixture

•CHARMM forcefield parameters for the model asphaltene molecule were predicted.•Similar properties were predicted for model asphalt components using both forcefields.•CHARMM forcefield correctly predicted the crystallization of n-docosane at 300 K.•Running asphalt mixture simulation using the CHARMM forcefield is promising.