Geometry optimization in redundant internal coordinates

P. Pulay, G. Fogarasi

Research output: Contribution to journalArticle

260 Citations (Scopus)


The gradient geometry-optimization procedure is reformulated in terms of redundant internal coordinates. By replacing the matrix inverse with the generalized inverse, the usual Newton-Raphson-type algorithms can be formulated in exactly the same way for redundant and nonredundant coordinates. Optimization in redundant coordinates is particularly useful for bridged polycyclic compounds and cage structures where it is difficult to define physically reasonable redundancy-free internal coordinates. This procedure, already used for the geometry optimization of porphine, C20N4H 14, is illustrated here at the ab initio self-consistent-field level for the four-membered ring azetidine, for bicyclo[2.2.2]octane, and for the four-ring system C16O2H22, the skeleton of taxol.

Original languageEnglish
Pages (from-to)2856-2860
Number of pages5
JournalThe Journal of Chemical Physics
Issue number4
Publication statusPublished - Jan 1 1992


ASJC Scopus subject areas

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

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