Instantaneous normal mode analysis of liquid HF

We present an instantaneous normal mode analysis of liquid HF aimed at clarifying the origin of peculiar dynamical properties which are supposed to stem from the un arrangement of molecules in a linear hydrogen-bonded network. The present study shows that this approach is a unique tool for the understanding of the spectral features revealed in the analysis of both single molecule and collective quantities. For the system under investigation, we demonstrate the relevance of hydrogen-bonding "stretching" and fast librational motion in the interpretation of these features.