Biomedical subjects

R Vallauri

Publications and source records attributed to R Vallauri.

12 recordsLinked to original sources

PubMed2000

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 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.

Journal Article↗

PubMed2000

Viscosity of liquid water from computer simulations with a polarizable potential model

The longitudinal and shear viscosity of water are calculated by molecular dynamics simulation with a polarizable potential model at room temperature. To overcome the difficulty of evaluating directly the stress autocorrelation function of a system with intrinsically many-body forces, we have resorted to the analysis of the wave-vector-dependent longitudinal and transverse-current correlation functions. In a memory function formalism, the generalized viscosity can be evaluated as a function of the wave vector k. By extrapolating to k=0, we find longitudinal and shear viscosity values in better agreement with the experimental value than the corresponding quantities evaluated by making use of a nonpolarizable potential model. This result points out that for a realistic reproduction of transport quantities, it is crucial to take into account many-body contributions to the interaction potential.

Journal Article↗

PubMed1995