Surface tension of the two center Lennard-Jones plus quadrupole model fluid

• The surface tension of quadrupolar model fluids is investigated by molecular dynamics simulation.
• 30 fluids are investigated covering the parameter range of 2CLJQ models for real fluids from the literature.
• An empirical correlation for the surface tension is developed as a global function of the model parameters.
• This work is the basis for a multi-criteria optimization of molecular models.

The surface tension is determined by molecular dynamics simulation for the class of fluid models containing two Lennard-Jones centers and a point quadrupole (2CLJQ). The simulations are carried out with a long range correction for elongated molecules at planar interfaces, along the whole vapor pressure curve. The model parameters are varied systematically, covering the parameter range of 2CLJQ models for real fluids from the literature. Vapor–liquid equilibrium properties are obtained which agree well with literature data for 2CLJQ models. An empirical correlation for the surface tension is developed as a global function of the model parameters.