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Toward a global maximization of the molecular similarity function: Superposition of two molecules


P. Constans, L. Amat, and R. Carbó-Dorca. Toward a global maximization of the molecular similarity function: Superposition of two molecules. Journal of Computational Chemistry, 18, 826-846 (1997).

A quantum similarity measure between two molecules is normally identified with the maximum value of the overlap of the corresponding molecular electron densities. The electron density overlap is a function of the mutual positioning of the compared molecules, requiring the measurement of similarity, a solution of a multiple-maxima problem. Collapsing the molecular electron densities into the nuclei provides the essential information toward a global maximization of the overlap similarity function, the maximization of which, in this limit case, appears to be related to the so-called assignment problem. Three levels of approach are then proposed for a global search scanning of the similarity function. In addition, atom]atom similarity Lorentzian potential functions are defined for a rapid completion of the function scanning. Performance is tested among these three levels of simplification and the Monte Carlo and simplex methods. Results reveal the present algorithms as accurate, rapid, and unbiased techniques for density-based molecular alignments.

Molecular quantum similarity measures MQSM, atomic shell approximation ASA, global maximization, molecular alignments, N-dimensional representation, diffusion equation method, Lennard-Jones atoms, dissimilar molecules, optimum structures, quantum objects, orbital bases, drug design, correspondences, deformation.

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