Ab initio generalized Langevin equation

Pinchen Xie, Roberto Car, E. Weinan

Research output: Contribution to journalArticlepeer-review

Abstract

We introduce a machine learning-based approach called ab initio generalized Langevin equation (AIGLE) to model the dynamics of slow collective variables (CVs) in materials and molecules. In this scheme, the parameters are learned from atomistic simulations based on ab initio quantum mechanical models. Force field, memory kernel, and noise generator are constructed in the context of the Mori-Zwanzig formalism, under the constraint of the fluctuation-dissipation theorem. Combined with deep potential molecular dynamics and electronic density functional theory, this approach opens the way to multiscale modeling in a variety of situations. Here, we demonstrate this capability with a study of two mesoscale processes in crystalline lead titanate, namely the field-driven dynamics of a planar ferroelectric domain wall, and the dynamics of an extensive lattice of coarse-grained electric dipoles. In the first case, AIGLE extends the reach of ab initio simulations to a regime of noise-driven motions not accessible to molecular dynamics. In the second case, AIGLE deals with an extensive set of CVs by adopting a local approximation for the memory kernel and retaining only short-range noise correlations. The scheme is computationally more efficient than molecular dynamics by several orders of magnitude and mimics the microscopic dynamics at low frequencies where it reproduces accurately the dominant far-infrared absorption frequency.

Original languageEnglish (US)
Article numbere2308668121
JournalProceedings of the National Academy of Sciences of the United States of America
Volume121
Issue number14
DOIs
StatePublished - Apr 2 2024

All Science Journal Classification (ASJC) codes

  • General

Keywords

  • generalized Langevin equation
  • machine learning
  • multiscale modeling

Fingerprint

Dive into the research topics of 'Ab initio generalized Langevin equation'. Together they form a unique fingerprint.

Cite this