Automatic parameterization of force fields for liquids by simplex optimization

We demonstrate an automatic method of force field development for molecular simulations. Parameter tuning is taken as an optimization problem in many dimensions. The parameters are automatically adapted to reproduce known experimental data such as the density and the heat of vaporization. Our method is more systematic than guessing parameters and, at the same time saves human labour in parameterization. It was successfully applied to several molecular liquids: As a test, force fields for 2-methylpentane, tetrahydrofurane, cyclohexene and cyclohexane were developed.