A parallel simplex search method for use with an automated chemistry workstation

The Simplex method, an inherently serial means of optimization, can be used to search for improved conditions for chemical reactions. We have developed an automated chemistry workstation equipped for parallel adaptive experimentation. To exploit the capabilities of the workstation and thereby optimize reaction conditions in a more expedient manner, we have developed an experiment-planning module for performing Simplex searches in parallel. The parallel Simplex search (PSS) module enables multiple composite modified Simplex (CMS) searches to be performed in a concurrent manner. Features have been incorporated for two applications. (1) Multiple concurrent simplex searches in one search space, enabling optimization of conditions for one reaction. The use of Simplex searches starting from several points in a search space reduces the possibility of falsely concluding that a local maximum is the global maximum. (2) Concurrent investigation of multiple search spaces with one Simplex search per space, enabling optimization of conditions for each member of a set of catalysts or set of reactants for a given reaction. This latter feature is useful for combinatorial chemistry applications. All individual Simplex searches in a PSS study must employ the same experimental template. The PSS module includes options to define conditions for simplex moves as well as specifying initial points in the search space. Provisions are included for stop criteria, termination of an individual Simplex search, and global termination of multiple Simplex searches. The PSS method provides a parallel yet adaptive means for identifying improved conditions for chemical reactions. (C) 2002 Elsevier Science B.V. All rights reserved.