Density-fragment interaction approach for quantum-mechanical/molecular-mechanical calculations with application to the excited states of a Mg(2+)-sensitive dye.

Journal Article (Journal Article)

A density-fragment interaction (DFI) approach for large-scale calculations is proposed. The DFI scheme describes electron density interaction between many quantum-mechanical (QM) fragments, which overcomes errors in electrostatic interactions with the fixed point-charge description in the conventional quantum-mechanical/molecular-mechanical (QM/MM) method. A self-consistent method, which is a mean-field treatment of the QM fragment interactions, was adopted to include equally the electron density interactions between the QM fragments. As a result, this method enables the evaluation of the polarization effects of the solvent and the protein surroundings. This method was combined with not only density functional theory (DFT) but also time-dependent DFT. In order to evaluate the solvent polarization effects in the DFI-QM/MM method, we have applied it to the excited states of the magnesium-sensitive dye, KMG-20. The DFI-QM/MM method succeeds in including solvent polarization effects and predicting accurately the spectral shift caused by Mg(2+) binding.

Full Text

Duke Authors

Cited Authors

  • Fujimoto, K; Yang, W

Published Date

  • August 2008

Published In

Volume / Issue

  • 129 / 5

Start / End Page

  • 054102 -

PubMed ID

  • 18698883

Pubmed Central ID

  • PMC2809692

Electronic International Standard Serial Number (EISSN)

  • 1089-7690

International Standard Serial Number (ISSN)

  • 0021-9606

Digital Object Identifier (DOI)

  • 10.1063/1.2958257


  • eng