Hydrogen fluoride is a hydrogen bonded system, which, contrary to water, has a layered structure in the crystalline phase, at ambient density. The liquid state of HF at low temperature and zero pressure is again different from liquid water, exhibiting two dimensional chain-like structures, as opposed to a three dimensional diamond-like network. In order to analyze the main differences between hydrogen bonding in H2O and HF, we have carried out a series of simulations in the liquid state, at low and high pressure (P=0, 10, 100 and 150 GPa) and at several temperatures.
Our results indicate that in the non dissociative regime, the effect of temperature on HF hydrogen bonding at small pressure is similar to that found for water. Furthermore, while very different at low pressure, liquid water and HF resemble each other at, e.g. 10GPa, hydrogen bonding being substantially weakened and molecules being arranged in a close-packed fashion in both systems. |
