### Abstract

A method for sampling efficiently the free energy landscape of a complex system with respect to some given collective variables is proposed. Inspired by metadynamics [A. Laio, M. Parrinello, Proc. Nat. Acad. Sci. USA 99 (2002) 12562], we introduce an extended system where the collective variables are treated as dynamical ones and show that this allows to sample the free energy landscape of these variables directly. The sampling is accelerated by using an artificially high temperature for the collective variables. The validity of the method is established using general results for systems with multiple time-scales, and its numerical efficiency is also discussed via error analysis. We also show how the method can be modified in order to sample the reactive pathways in free energy space, and thereby analyze the mechanism of a reaction. Finally, we discuss how the method can be generalized and used as an alternative to the Kirkwood generalized thermodynamic integration approach for the calculation of free energy differences.

Original language | English (US) |
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Pages (from-to) | 168-175 |

Number of pages | 8 |

Journal | Chemical Physics Letters |

Volume | 426 |

Issue number | 1-3 |

DOIs | |

State | Published - Jul 26 2006 |

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### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Spectroscopy
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces
- Condensed Matter Physics

### Cite this

**A temperature accelerated method for sampling free energy and determining reaction pathways in rare events simulations.** / Maragliano, Luca; Vanden Eijnden, Eric.

Research output: Contribution to journal › Article

*Chemical Physics Letters*, vol. 426, no. 1-3, pp. 168-175. https://doi.org/10.1016/j.cplett.2006.05.062

}

TY - JOUR

T1 - A temperature accelerated method for sampling free energy and determining reaction pathways in rare events simulations

AU - Maragliano, Luca

AU - Vanden Eijnden, Eric

PY - 2006/7/26

Y1 - 2006/7/26

N2 - A method for sampling efficiently the free energy landscape of a complex system with respect to some given collective variables is proposed. Inspired by metadynamics [A. Laio, M. Parrinello, Proc. Nat. Acad. Sci. USA 99 (2002) 12562], we introduce an extended system where the collective variables are treated as dynamical ones and show that this allows to sample the free energy landscape of these variables directly. The sampling is accelerated by using an artificially high temperature for the collective variables. The validity of the method is established using general results for systems with multiple time-scales, and its numerical efficiency is also discussed via error analysis. We also show how the method can be modified in order to sample the reactive pathways in free energy space, and thereby analyze the mechanism of a reaction. Finally, we discuss how the method can be generalized and used as an alternative to the Kirkwood generalized thermodynamic integration approach for the calculation of free energy differences.

AB - A method for sampling efficiently the free energy landscape of a complex system with respect to some given collective variables is proposed. Inspired by metadynamics [A. Laio, M. Parrinello, Proc. Nat. Acad. Sci. USA 99 (2002) 12562], we introduce an extended system where the collective variables are treated as dynamical ones and show that this allows to sample the free energy landscape of these variables directly. The sampling is accelerated by using an artificially high temperature for the collective variables. The validity of the method is established using general results for systems with multiple time-scales, and its numerical efficiency is also discussed via error analysis. We also show how the method can be modified in order to sample the reactive pathways in free energy space, and thereby analyze the mechanism of a reaction. Finally, we discuss how the method can be generalized and used as an alternative to the Kirkwood generalized thermodynamic integration approach for the calculation of free energy differences.

UR - http://www.scopus.com/inward/record.url?scp=33745762636&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33745762636&partnerID=8YFLogxK

U2 - 10.1016/j.cplett.2006.05.062

DO - 10.1016/j.cplett.2006.05.062

M3 - Article

VL - 426

SP - 168

EP - 175

JO - Chemical Physics Letters

JF - Chemical Physics Letters

SN - 0009-2614

IS - 1-3

ER -