Increasing the time step with mass scaling in born-oppenheimer ab Initio QM/MM molecular dynamics simulations

Han Zheng, Shenglong Wang, Yingkai Zhang

Research output: Contribution to journalArticle

Abstract

Born-Oppenheimer ab initio QM/MM molecular dynamics simulation with umbrella sampling is a state-of-the-art approach to calculate free energy profiles of chemical reactions in complex systems. To further improve its computational efficiency, a mass-scaling method with the increased time step in MD simulations has been explored and tested. It is found that by increasing the hydrogen mass to 10 amu, a time step of 3 fs can be employed in ab initio QM/MM MD simulations. In all our three test cases, including two solution reactions and one enzyme reaction, the resulted reaction free energy profiles with 3 fs time step and mass scaling are found to be in excellent agreement with the corresponding simulation results using 1 fs time step and the normal mass. These results indicate that for Born-Oppenheimer ab initio QM/MM molecular dynamics simulations with umbrella sampling, the mass-scaling method can significantly reduce its computational cost while has little effect on the calculated free energy profiles.

Original languageEnglish (US)
Pages (from-to)2706-2711
Number of pages6
JournalJournal of Computational Chemistry
Volume30
Issue number16
DOIs
StatePublished - Dec 2009

Keywords

  • Ab initio QM/MM method
  • Free energy profile
  • Molecular dynamics simulation
  • Time step
  • Umbrella sampling

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics

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