title: Quantum Thermal Bath for Path Integral Molecular Dynamics Simulation.
abstract: The quantum thermal bath (QTB) method has been recently developed to account for the quantum nature of the nuclei by using standard molecular dynamics (MD) simulation. QTB-MD is an efficient but approximate method when dealing with strongly anharmonic systems, while path integral molecular dynamics (PIMD) gives exact results but in a huge amount of computation time. The QTB and PIMD methods have been combined in order to improve the PIMD convergence or correct the failures of the QTB-MD technique. Therefore, a new power spectral density of the random force within the QTB has been developed. A modified centroid-virial estimator of the kinetic energy, especially adapted to QTB-PIMD, has also been proposed. The method is applied to selected systems: a one-dimensional double-well system, a ferroelectric phase transition, and the position distribution of an hydrogen atom in a fuel cell material. The advantage of the QTB-PIMD method is its ability to give exact results with a more reasonable computation time for strongly anharmonic systems.
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, CNRS, Université Paris-Saclay , F-92295 Châtenay-Malabry, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Brieuc
authors.affiliation: Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, CNRS, Université Paris-Saclay , F-92295 Châtenay-Malabry, France.|Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay , F-91128 Palaiseau, France.
authors.forename: Hichem
authors.initials: H
authors.lastname: Dammak
authors.affiliation: Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay , F-91128 Palaiseau, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Hayoun