Construction of an accurate quartic force field by using generalised least-squares fitting and experimental design

Philippe Carbonnière (1) , Didier Bégué (1) , Alain Dargelos (1) , Claude Pouchan (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

In this work we present an attractive least-squares fitting procedure which allows for the calculation of a quartic force field by jointly using energy, gradient, and Hessian data, obtained from electronic wave function calculations on a suitably chosen grid of points. We use the experimental design to select the grid points: a "simplex-sum" of Box and Behnken grid was chosen for its efficiency and accuracy. We illustrate the numerical implementations of the method by using the energy and gradient data for H 2O and H2CO. The B3LYP/cc-pVTZ quartic force field performed from 11 and 44 simplex-sum configurations shows excellent agreement in comparison to the classical 44 and 168 energy calculations. © 2004 Elsevier B.V. All rights reserved.

Domaines: Chimie théorique et/ou physique

Philippe Carbonnière, Didier Bégué, Alain Dargelos, Claude Pouchan. Construction of an accurate quartic force field by using generalised least-squares fitting and experimental design. Chemical Physics, 2004, 300 (1-3), pp.41-51. ⟨10.1016/j.chemphys.2004.01.007⟩. ⟨hal-01598749⟩