Predicting molecular structures application of the cutting angle method.pdf

Predicting molecular structures: an application of the cutting angle method Kieran F. Lim,ya Gleb Beliakov*b and Lynn M. Battenb a Centre for Chiral and Molecular Technologies, School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria 3217, Australia b School of Information Technology, Deakin University, Burwood, Victoria 2135, Australia. E-mail: gleb@.au Received 21st May 2003, Accepted 23rd July 2003 First published as an Advance Article on the web 11th August 2003 The ability to predict molecular geometries has important applications in chemistry. Specific examples include the areas of protein space structure elucidation, the investigation of host–guest interactions, the understanding of properties of superconductors and of zeolites. This prediction of molecular geometries often depends on finding the global minimum or maximum of a function such as the potential energy. In this paper, we consider several well-known molecular conformation problems to which we apply a new method of deterministic global optimization called the cutting angle method. We demonstrate that this method is competitive with other global optimization techniques for these molecular conformation problems. Introduction Many problems in chemistry depend on the ability to identify the global minimum or maximum of a function. Examples include important applications in chemometrics,1 flow rates or pH concentrations in the optimization of flow analysis methods,2–4 statistical process control in manufacturing, the maximization of yields in synthesis and manufacturing, non- linear least-squares analysis and the ability to predict molecu- lar geometries. In particular, the last-mentioned application includes the areas of protein space structure elucidation, the investigation of host–guest interactions, the understanding of properties of superconductors and zeolites,5 and the identifica- tion of transition states.6 In all of these situations, one needs to find the molecular geomet