Improving the efficiency of branch-and-bound complete-search NMR assignment using the symmetry of molecules and spectra

Andrés Mauricio Castillo Robles, Luc Patiny, Julien Wist
Amer Inst Physics, 2015
Journal paper

Abstract

Nuclear magnetic resonance (NMR) assignment of small molecules is presented as a typical example of a combinatorial optimization problem in chemical physics. Three strategies that help improve the efficiency of solution search by the branch and bound method are presented: 1. reduction of the size of the solution space by resort to a condensed structure formula, wherein symmetric nuclei are grouped together; 2. partitioning of the solution space based on symmetry, that becomes the basis for an efficient branching procedure; and 3. a criterion of selection of input restrictions that leads to increased gaps between branches and thus faster pruning of non-viable solutions. Although the examples chosen to illustrate this work focus on small-molecule NMR assignment, the results are generic and might help solving other combinatorial optimization problems. (C) 2015 AIP Publishing LLC.

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