Finite-Temperature Dimer Method for Finding Saddle Points on Free Energy Surfaces

Huan Zhang, Lili Qiu, Dan Hu

    Research output: Contribution to journalArticle

    Abstract

    The dimer method and its variants have been shown to be efficient in finding saddle points on potential surfaces. In the dimer method, the most unstable direction is approximately obtained by minimizing the total potential energy of the dimer. Then, the force in this direction is reversed to move the dimer toward saddle points. When the finite-temperature effect is important for a high-dimensional system, one usually needs to describe the dynamics in a low-dimensional space of reaction coordinates. In this case, transition states are collected as saddle points on the free energy surface. The traditional dimer method cannot be directly employed to find saddle points on a free energy surface since the surface is not known a priori. Here, we develop a finite-temperature dimer method for searching saddle points on the free energy surface. In this method, a constrained rotation dynamics of the dimer system is used to sample dimer directions and an efficient average method is used to obtain a good approximation of the most unstable direction. This approximated direction is then used in reversing the force component and evolving the dimer toward saddle points. Our numerical results suggest that the new method is efficient in finding saddle points on free energy surfaces.

    Original languageEnglish (US)
    JournalJournal of Computational Chemistry
    DOIs
    StatePublished - Jan 1 2019

    Fingerprint

    Dimer
    Finite Temperature
    Saddlepoint
    Dimers
    Free energy
    Free Energy
    Temperature
    Unstable
    Surface Potential
    Transition State
    Temperature Effect
    Surface potential
    Potential energy
    Thermal effects
    High-dimensional
    Direction compound
    Numerical Results
    Approximation
    Energy

    Keywords

    • dimer method
    • free energy surface
    • rare event
    • saddle point
    • transition path

    ASJC Scopus subject areas

    • Chemistry(all)
    • Computational Mathematics

    Cite this

    Finite-Temperature Dimer Method for Finding Saddle Points on Free Energy Surfaces. / Zhang, Huan; Qiu, Lili; Hu, Dan.

    In: Journal of Computational Chemistry, 01.01.2019.

    Research output: Contribution to journalArticle

    @article{244df6bfc8d9458e9b5b1433c07d2f10,
    title = "Finite-Temperature Dimer Method for Finding Saddle Points on Free Energy Surfaces",
    abstract = "The dimer method and its variants have been shown to be efficient in finding saddle points on potential surfaces. In the dimer method, the most unstable direction is approximately obtained by minimizing the total potential energy of the dimer. Then, the force in this direction is reversed to move the dimer toward saddle points. When the finite-temperature effect is important for a high-dimensional system, one usually needs to describe the dynamics in a low-dimensional space of reaction coordinates. In this case, transition states are collected as saddle points on the free energy surface. The traditional dimer method cannot be directly employed to find saddle points on a free energy surface since the surface is not known a priori. Here, we develop a finite-temperature dimer method for searching saddle points on the free energy surface. In this method, a constrained rotation dynamics of the dimer system is used to sample dimer directions and an efficient average method is used to obtain a good approximation of the most unstable direction. This approximated direction is then used in reversing the force component and evolving the dimer toward saddle points. Our numerical results suggest that the new method is efficient in finding saddle points on free energy surfaces.",
    keywords = "dimer method, free energy surface, rare event, saddle point, transition path",
    author = "Huan Zhang and Lili Qiu and Dan Hu",
    year = "2019",
    month = "1",
    day = "1",
    doi = "10.1002/jcc.25824",
    language = "English (US)",
    journal = "Journal of Computational Chemistry",
    issn = "0192-8651",
    publisher = "John Wiley and Sons Inc.",

    }

    TY - JOUR

    T1 - Finite-Temperature Dimer Method for Finding Saddle Points on Free Energy Surfaces

    AU - Zhang, Huan

    AU - Qiu, Lili

    AU - Hu, Dan

    PY - 2019/1/1

    Y1 - 2019/1/1

    N2 - The dimer method and its variants have been shown to be efficient in finding saddle points on potential surfaces. In the dimer method, the most unstable direction is approximately obtained by minimizing the total potential energy of the dimer. Then, the force in this direction is reversed to move the dimer toward saddle points. When the finite-temperature effect is important for a high-dimensional system, one usually needs to describe the dynamics in a low-dimensional space of reaction coordinates. In this case, transition states are collected as saddle points on the free energy surface. The traditional dimer method cannot be directly employed to find saddle points on a free energy surface since the surface is not known a priori. Here, we develop a finite-temperature dimer method for searching saddle points on the free energy surface. In this method, a constrained rotation dynamics of the dimer system is used to sample dimer directions and an efficient average method is used to obtain a good approximation of the most unstable direction. This approximated direction is then used in reversing the force component and evolving the dimer toward saddle points. Our numerical results suggest that the new method is efficient in finding saddle points on free energy surfaces.

    AB - The dimer method and its variants have been shown to be efficient in finding saddle points on potential surfaces. In the dimer method, the most unstable direction is approximately obtained by minimizing the total potential energy of the dimer. Then, the force in this direction is reversed to move the dimer toward saddle points. When the finite-temperature effect is important for a high-dimensional system, one usually needs to describe the dynamics in a low-dimensional space of reaction coordinates. In this case, transition states are collected as saddle points on the free energy surface. The traditional dimer method cannot be directly employed to find saddle points on a free energy surface since the surface is not known a priori. Here, we develop a finite-temperature dimer method for searching saddle points on the free energy surface. In this method, a constrained rotation dynamics of the dimer system is used to sample dimer directions and an efficient average method is used to obtain a good approximation of the most unstable direction. This approximated direction is then used in reversing the force component and evolving the dimer toward saddle points. Our numerical results suggest that the new method is efficient in finding saddle points on free energy surfaces.

    KW - dimer method

    KW - free energy surface

    KW - rare event

    KW - saddle point

    KW - transition path

    UR - http://www.scopus.com/inward/record.url?scp=85063130218&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85063130218&partnerID=8YFLogxK

    U2 - 10.1002/jcc.25824

    DO - 10.1002/jcc.25824

    M3 - Article

    JO - Journal of Computational Chemistry

    JF - Journal of Computational Chemistry

    SN - 0192-8651

    ER -