2006/01/01 by Marcel Swart, F. Matthias Bickelhaupt · 112 citations
Chemistry · Mathematics · Physics and Astronomy · #Action-angle coordinates #Advanced Chemical Physics Studies #Algorithm #Applied mathematics #Bipolar coordinates #Chemistry #Computation #Computational chemistry #Computer science #Delocalized electron #Function (biology) #Generalized coordinates #Geometry #Hessian matrix #Log-polar coordinates #Mathematics #Matrix (chemical analysis) #Molecular spectroscopy and chirality #Orthogonal coordinates #Parabolic coordinates #Physics #Quantum mechanics #Set (abstract data type) #Spectroscopy and Quantum Chemical Studies #State (computer science)
paper · doi:10.1002/qua.21049
published in International Journal of Quantum Chemistry 106(12), 2536-2544 (Wiley)
openalex publication_date 2006/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom‐pair distances to differentiate strong coordinates from weak coordinates. This differentiation significantly accelerates the optimization of these coordinates, and thus of the overall geometry. An adapted version of the delocalized coordinates setup is used to generate automatically a set of internal coordinates that is shown to perform well for the geometry optimization of systems with weak and strong coordinates. For the Baker test set of 30 molecules, we need only 173 geometry cycles with PW91/TZ2P calculations, which compares well with the best previous attempts reported in literature. For the localization of transition state structures, we generate the initial Hessian matrix, using appropriate force constants from a database. In this way, one avoids the explicit computation of the Hessian matrix. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006