Markov-type state models to describe non-Markovian dynamics

Fuente: arXiv
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Main Authors: Sartore, Sofia, Teichmann, Franziska, Stock, Gerhard
Format: Preprint
Published: 2024
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author Sartore, Sofia
Teichmann, Franziska
Stock, Gerhard
author_facet Sartore, Sofia
Teichmann, Franziska
Stock, Gerhard
contents When clustering molecular dynamics (MD) trajectories into a few metastable conformational states, the Markov state models (MSMs) assumption of timescale separation between fast intrastate fluctuations and rarely occurring interstate transitions is often not valid. Hence, the naive estimation of the macrostate transition matrix via simply counting transitions between the states leads to significantly too short implied timescales and thus to too fast population decays. In this work, we discuss advanced approaches to estimate the transition matrix. Assuming that Markovianity is at least given at the microstate level, we consider the Laplace-transform based method by Hummer and Szabo, as well as a direct microstate-to-macrostate projection, which by design yields correct macrostate population dynamics. Alternatively, we study the recently proposed quasi-MSM ansatz of Huang and coworkers to solve a generalized master equations, as well as a hybrid method that employs MD at short times and MSM at long times. Adopting a one-dimensional toy model and an all-atom folding trajectory of HP35, we discuss the virtues and shortcomings of the various approaches.
format Preprint
id arxiv_https___arxiv_org_abs_2412_08660
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Markov-type state models to describe non-Markovian dynamics
Sartore, Sofia
Teichmann, Franziska
Stock, Gerhard
Soft Condensed Matter
Biological Physics
Computational Physics
Data Analysis, Statistics and Probability
When clustering molecular dynamics (MD) trajectories into a few metastable conformational states, the Markov state models (MSMs) assumption of timescale separation between fast intrastate fluctuations and rarely occurring interstate transitions is often not valid. Hence, the naive estimation of the macrostate transition matrix via simply counting transitions between the states leads to significantly too short implied timescales and thus to too fast population decays. In this work, we discuss advanced approaches to estimate the transition matrix. Assuming that Markovianity is at least given at the microstate level, we consider the Laplace-transform based method by Hummer and Szabo, as well as a direct microstate-to-macrostate projection, which by design yields correct macrostate population dynamics. Alternatively, we study the recently proposed quasi-MSM ansatz of Huang and coworkers to solve a generalized master equations, as well as a hybrid method that employs MD at short times and MSM at long times. Adopting a one-dimensional toy model and an all-atom folding trajectory of HP35, we discuss the virtues and shortcomings of the various approaches.
title Markov-type state models to describe non-Markovian dynamics
topic Soft Condensed Matter
Biological Physics
Computational Physics
Data Analysis, Statistics and Probability
url https://arxiv.org/abs/2412.08660