Simplified and improved string method for computing the minimum energy paths in barrier-crossing events

Weinan E, Weiqing Ren, Eric Vanden-Eijnden

Research output: Contribution to journalArticle


We present a simplified and improved version of the string method, originally proposed by E [Phys. Rev. B 66, 052301 (2002)] for identifying the minimum energy paths in barrier-crossing events. In this new version, the step of projecting the potential force to the direction normal to the string is eliminated and the full potential force is used in the evolution of the string. This not only simplifies the numerical procedure, but also makes the method more stable and accurate. We discuss the algorithmic details of the improved string method, analyze its stability, accuracy and efficiency, and illustrate it via numerical examples. We also show how the string method can be combined with the climbing image technique for the accurate calculation of saddle points and we present another algorithm for the accurate calculation of the unstable directions at the saddle points.

Original languageEnglish (US)
Article number164103
JournalJournal of Chemical Physics
Issue number16
StatePublished - Jan 1 2007


ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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