title: Simulating Energy Relaxation in Pump-Probe Vibrational Spectroscopy of Hydrogen-Bonded Liquids.
abstract: We introduce a nonequilibrium molecular dynamics simulation approach, based on the generalized Langevin equation, to study vibrational energy relaxation in pump-probe spectroscopy. A colored noise thermostat is used to selectively excite a set of vibrational modes, leaving the other modes nearly unperturbed, to mimic the effect of a monochromatic laser pump. Energy relaxation is probed by analyzing the evolution of the system after excitation in the microcanonical ensemble, thus providing direct information about the energy redistribution paths at the molecular level and their time scale. The method is applied to hydrogen-bonded molecular liquids, specifically deuterated methanol and water, providing a robust picture of energy relaxation at the molecular scale.
authors.affiliation: Dipartimento di Fisica, Università di Cagliari , Cittadella Universitaria, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Dettori
authors.affiliation: Laboratory of Computational Science and Modeling, IMX, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland.
authors.forename: Michele
authors.initials: M
authors.lastname: Ceriotti
authors.affiliation: Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Hunger
authors.affiliation: Dipartimento di Fisica, Università di Cagliari , Cittadella Universitaria, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Melis
authors.affiliation: Dipartimento di Fisica, Università di Cagliari , Cittadella Universitaria, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Luciano
authors.identifier: http://orcid.org/0000-0001-5335-4652
authors.initials: L
authors.lastname: Colombo
authors.affiliation: Department of Chemistry, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Davide
authors.identifier: http://orcid.org/0000-0002-2150-4182
authors.initials: D
authors.lastname: Donadio