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Shadow Molecular Dynamics and Atomic Cluster Expansions for Flexible Charge Models.
Goff, James; Zhang, Yu; Negre, Christian; Rohskopf, Andrew; Niklasson, Anders M N.
Afiliación
  • Goff J; Center for Computing and Research, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States.
  • Zhang Y; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
  • Negre C; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
  • Rohskopf A; Center for Computing and Research, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States.
  • Niklasson AMN; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
J Chem Theory Comput ; 19(13): 4255-4272, 2023 Jul 11.
Article en En | MEDLINE | ID: mdl-37382528
A shadow molecular dynamics scheme for flexible charge models is presented where the shadow Born-Oppenheimer potential is derived from a coarse-grained approximation of range-separated density functional theory. The interatomic potential, including the atomic electronegativities and the charge-independent short-range part of the potential and force terms, is modeled by the linear atomic cluster expansion (ACE), which provides a computationally efficient alternative to many machine learning methods. The shadow molecular dynamics scheme is based on extended Lagrangian (XL) Born-Oppenheimer molecular dynamics (BOMD) [Eur. Phys. J. B 2021, 94, 164]. XL-BOMD provides stable dynamics while avoiding the costly computational overhead associated with solving an all-to-all system of equations, which normally is required to determine the relaxed electronic ground state prior to each force evaluation. To demonstrate the proposed shadow molecular dynamics scheme for flexible charge models using atomic cluster expansion, we emulate the dynamics generated from self-consistent charge density functional tight-binding (SCC-DFTB) theory using a second-order charge equilibration (QEq) model. The charge-independent potentials and electronegativities of the QEq model are trained for a supercell of uranium oxide (UO2) and a molecular system of liquid water. The combined ACE+XL-QEq molecular dynamics simulations are stable over a wide range of temperatures both for the oxide and for the molecular systems and provide a precise sampling of the Born-Oppenheimer potential energy surfaces. Accurate ground Coulomb energies are produced by the ACE-based electronegativity model during an NVE simulation of UO2, predicted to be within 1 meV of those from SCC-DFTB on average during comparable simulations.

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Tipo de estudio: Prognostic_studies Idioma: En Revista: J Chem Theory Comput Año: 2023 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Tipo de estudio: Prognostic_studies Idioma: En Revista: J Chem Theory Comput Año: 2023 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos