MixPI: Mixed-Time Slicing Path Integral Software for Quantized Molecular Dynamics Simulations

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Johnson, Britta A., Bu, Siyu, Mundy, Christopher J., Ananth, Nandini
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917840779476992
author Johnson, Britta A.
Bu, Siyu
Mundy, Christopher J.
Ananth, Nandini
author_facet Johnson, Britta A.
Bu, Siyu
Mundy, Christopher J.
Ananth, Nandini
contents Path Integral Molecular Dynamics (PIMD) is a well established simulation technique to compute exact equilibrium properties for a quantum system using classical trajectories in an extended phase space. Standard PIMD simulations are numerically converged by systematically increasing the number of classical 'beads' or replicas used to represent each particle in the quantum system. Currently available scientific software for PIMD simulations leverage the massively parallel (with respect to number of beads) nature of the classical PIMD Hamiltonian. For particularly high-dimensional systems, contraction schemes designed to reduce the overall number of beads per particle required to achieve numerical convergence are also frequently employed. However, these implementations all rely on using the same number of beads to represent all atoms/particles, and become inefficient in systems with a large number of atoms where only a handful contribute significant quantum effects. Mixed time slicing (mixTS) offers an alternate path to efficient PIMD simulations by providing a framework where numerical convergence can be achieved with different numbers of beads for different types of atoms. Unfortunately, mixTS is not available in existing PIMD software. In this paper, we introduce MixPI for atomistic mixTS-PIMD simulations within the open-source software package CP2K. We demonstrate the use of MixPI in two different benchmark systems: we explore the use of mixTS in computing radial distributions functions for water, and in a more significant demonstration, for a solvated Co2+ ion represented as a classical Co3+ ion in water with an explicit, quantized 1024-bead electron localized on the metal ion.
format Preprint
id arxiv_https___arxiv_org_abs_2411_11988
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle MixPI: Mixed-Time Slicing Path Integral Software for Quantized Molecular Dynamics Simulations
Johnson, Britta A.
Bu, Siyu
Mundy, Christopher J.
Ananth, Nandini
Chemical Physics
Path Integral Molecular Dynamics (PIMD) is a well established simulation technique to compute exact equilibrium properties for a quantum system using classical trajectories in an extended phase space. Standard PIMD simulations are numerically converged by systematically increasing the number of classical 'beads' or replicas used to represent each particle in the quantum system. Currently available scientific software for PIMD simulations leverage the massively parallel (with respect to number of beads) nature of the classical PIMD Hamiltonian. For particularly high-dimensional systems, contraction schemes designed to reduce the overall number of beads per particle required to achieve numerical convergence are also frequently employed. However, these implementations all rely on using the same number of beads to represent all atoms/particles, and become inefficient in systems with a large number of atoms where only a handful contribute significant quantum effects. Mixed time slicing (mixTS) offers an alternate path to efficient PIMD simulations by providing a framework where numerical convergence can be achieved with different numbers of beads for different types of atoms. Unfortunately, mixTS is not available in existing PIMD software. In this paper, we introduce MixPI for atomistic mixTS-PIMD simulations within the open-source software package CP2K. We demonstrate the use of MixPI in two different benchmark systems: we explore the use of mixTS in computing radial distributions functions for water, and in a more significant demonstration, for a solvated Co2+ ion represented as a classical Co3+ ion in water with an explicit, quantized 1024-bead electron localized on the metal ion.
title MixPI: Mixed-Time Slicing Path Integral Software for Quantized Molecular Dynamics Simulations
topic Chemical Physics
url https://arxiv.org/abs/2411.11988