Inexpensive modeling of quantum dynamics using path integral generalized Langevin equation thermostats
Creators
- 1. Laboratory of Computational Science and Modelling, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
* Contact person
Description
The properties of molecules and materials containing light nuclei are affected by their quantum mechanical nature. Accurate modeling of these quantum nuclear effects requires computationally demanding path integral techniques. Considerable success has been achieved in reducing the cost of such simulations by using generalized Langevin dynamics to induce frequency-dependent fluctuations. Path integral generalized Langevin equation methods, however, have this far been limited to the study of static, thermodynamic properties due to the large perturbation to the system's dynamics induced by the aggressive thermostatting. Here, we introduce a post-processing scheme, based on analytical estimates of the dynamical perturbation induced by the generalized Langevin dynamics, which makes it possible to recover meaningful time correlation properties from a thermostatted trajectory. We show that this approach yields spectroscopic observables for model and realistic systems that have an accuracy comparable to much more demanding approximate quantum dynamics techniques based on full path integral simulations.
Files
File preview
files_description.md
All files
References
Journal reference (The paper contains the method and the data) V. Kapil, D. M. Wilkins, J. Lan, M. Ceriotti, The Journal of Chemical Physics, vol. 152, no. 12, Mar. 2020, p. 124104., doi: 10.1063/1.5141950
Journal reference (The paper contains the method and the data) V. Kapil, D. M. Wilkins, J. Lan, M. Ceriotti, The Journal of Chemical Physics, vol. 152, no. 12, Mar. 2020, p. 124104.
Preprint V. Kapil, D. M. Wilkins, J. Lan, M. Ceriotti, arXiv:1912.03189