A new ONIOM implementation in Gaussian98. Part I. The calculation of energies, gradients, vibrational frequencies and electric field derivatives

Stefan Dapprich, István Komáromi, K. Suzie Byun, Keiji Morokuma, Michael J. Frisch

Research output: Contribution to journalArticle

1704 Citations (Scopus)

Abstract

The IMOMM, IMOMO, and ONIOM methods have been proven to be powerful tools for the theoretical treatment of large molecular systems where different levels of theory are applied to different parts of a molecule. Within this framework we present a modified handling of the link atoms which are introduced to terminate the dangling bonds of the model system. Using this new scheme the definition of the combined energy gradient, the Hessian matrix, and the integration of higher derivatives of the energy with respect to nuclear coordinates and the electric field vector becomes straightforward. This allows for the first time the consistent combination of vibrational frequencies and the calculation of other molecular properties such as IR intensities, Raman intensities as well as dipole moments, polarizabilities, and hyperpolarizabilities. Test calculations for some typical as well as unusual examples and partitioning schemes are presented to demonstrate the power and limitations of the method and to provide guidelines for its applicability. Users of the method are strongly advised to test, calibrate and confirm for themselves the validity of the method combination and the model subsystem for the properties they want to calculate.

Original languageEnglish
Pages (from-to)1-21
Number of pages21
JournalJournal of Molecular Structure: THEOCHEM
Volume461-462
DOIs
Publication statusPublished - Apr 2 1999

Keywords

  • Ab initio methods
  • Energy gradients
  • Molecular properties
  • ONIOM

ASJC Scopus subject areas

  • Biochemistry
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

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