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Download fileEnergy Relaxation and Thermal Diffusion in Infrared Pump–Probe Spectroscopy of Hydrogen-Bonded Liquids
journal contribution
posted on 2019-06-03, 00:00 authored by Riccardo Dettori, Michele Ceriotti, Johannes Hunger, Luciano Colombo, Davide DonadioInfrared
pump–probe spectroscopy provides detailed information
about the dynamics of hydrogen-bonded liquids. Due to dissipation
of the absorbed pump pulse energy, thermal equilibration dynamics
also contributes to the observed signal. Disentangling this contribution
from the molecular response remains a challenge. By performing non-equilibrium
molecular dynamics simulations of liquid-deuterated methanol, we show
that faster molecular vibrational relaxation and slower heat diffusion
are decoupled and occur on different length scales. Transient structures
of the hydrogen bonding network influence thermal relaxation by affecting
thermal diffusivity over a length scale of several nanometers.