A numerically stable restrained electrostatic potential charge fitting method

Juan Zeng, Lili Duan, John Z.H. Zhang, Ye Mei

Research output: Contribution to journalArticle


Inspired by the idea of charge decomposition in calculation of the dipole preserving and polarization consistent charges (Zhang et al., J. Comput. Chem. 2011, 32, 2127), we have proposed a numerically stable restrained electrostatic potential (ESP)-based charge fitting method for protein. The atomic charge is composed of two parts. The dominant part is fixed to a predefined value (e.g., AMBER charge), and the residual part is to be determined by restrained fitting to residual ESP on grid points around the molecule. Nonuniform weighting factors as a function of the dominant charge are assigned to the atoms. Because the residual part is several folds to several orders smaller than the dominant part, the impact of ill-conditioning is alleviated. This charge fitting method can be used in quantum mechanical/molecular mechanical (QM/MM) simulations and similar studies, where QM calculated electronic properties are frequently mapped to partial atomic charges.

Original languageEnglish (US)
Pages (from-to)847-853
Number of pages7
JournalJournal of Computational Chemistry
Issue number10
StatePublished - Apr 5 2013



  • charge fit
  • molecular mechanics
  • numerical stability
  • restrained electrostatic potential

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics

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