An extensional Tra PPE-UA force field for N,N-dimethyl-formamide(DMF) was developed by combination of the quantum chemistry calculation and Gibbs ensemble Monte Carlo simulation, which lays the foundation for the simulation of vapor-liquid phase equilibrium with DMF. First of all, the vapor-liquid phase equilibrium for DMF was calculated in the NVT-Gibbs ensemble by using this new force filed. The results show that the new force field can be used to accurately calculate the saturated liquid densities, vapor...