Structural Properties of Hydrogen Fluoride in Aqueous Solution Using Reactive Force Field

The dynamics of hydrogen fluoride in aqueous solutions at the atomic scale cannot easily be analyzed experimentally and computationally because of the high reactivity of hydrogen fluoride (HF). To elucidate the behavior and growth process of HF aqueous solutions, this study investigated geometric and energetic properties using molecular dynamics simulations with a reactive force field. First, we examined that the previously proposed reactive force field operates properly in bulk HF aqueous solution systems in terms of bond lengths, vibrational frequencies, and dissociation states. Furthermore, the dimer and trimer structures of the HF molecules corresponded to a stable structure with HF parallel shape, reported using ab initio calculations in an isolated environment. Although large clusters grew in combinations based on the parallel geometry of (HF)₂, their interaction with water molecules tended to limit their growth in certain directions relative to the HF molecule. The clusters had mainly two layers of F atoms that spread and grew in the planar direction. These findings would provide valuable insights into the design of nanoscale devices, paving the way for new semiconductor manufacturing processes.