Quantitative Analysis of Organic-Metal Interactions—New IFF MD Models, Get it Right

Interactions of elemental metals with organic molecules are critical for applications like catalysis, material science, and therapeutics. However, up to now, high-quality and systematic experimental data are still very rare. In this work, we show that molecular dynamics (MD) simulations with the Interface force field (IFF) predict the adsorption of benzene and naphthalene molecules on Pt(111) surfaces in only 5% error across a wide range of surface coverage relative to such rare measurements, without additional fit parameters. Such high accuracy and systematic correlation have never been achieved by any other simulation method. Surface structural changes and the heat of adsorption are precisely examined, found to be 7 times more reliable than with CHARMM36 force field, and 14 times than with density functional theory (DFT) based methods at millions of times faster speed. The atomic-level comparisons revealed that small concave defects lead to larger heat of adsorption while large terraces and islands lead to similar heat of adsorption in comparison to perfect Pt(111) surfaces. The astonishing reliability and speed can be harnessed to answer a broad range of questions on many metal interfaces. The innovative methods can be consistently applied and extended to a variety of organic- metal systems.