DFT and molecular dynamic simulation for the dielectric property analysis of polyimides

The dielectric properties of polyimides were analyzed by different theoretical methods, including the density functional theory (DFT) calculation for dielectric constant prediction and the molecular dynamic simulation for dielectric performance explanation. The best functional/basis set combinations are optimized to be CAM-B3LYP and 6–311++g(d,p) in DFT study. On the other hand, the molecular parameters of band gap, chain mobility, solubility parameter and fractional free volume were simulated and the latter two show high correlation with the dielectric constant. This work is the starting point for developing a reliable and efficient database to accelerate the overall process toward low dielectric-constant polymer discovery.