Applying the constraint satisfaction problem paradigm to structure generation

Abstract

sponding NMR, IR data, and the molecular formula. Other substructural inferences, mainly from 2D NMR experiments, are retrospectively used to constrain the generation process.

HOUDINI: A New Approach to Computer-Based Structure Generation

“…A recently described structure generator, Program LSD, 27 which is based on the CSP paradigm, resolves that shortcoming by mapping all of the substructural atoms in an arbitrary order. The process is similar to but more efficient than that of GENOA, because LSD uses required substructures in a more concerted way.…”

“…The output of LSD is similar to GENOA's final "cases" (i.e., partial structures), each of which is then expanded to a set of complete molecules. In the structure problems studied, 27 a large number of complete molecular structures, including some highly strained, were obtained.…”

Computer assisted structure elucidation of natural products using two-dimensional NMR spectroscopy†

“…29 LSD accomplishes structure generation by treating it as a constraint satisfaction problem which is solved using constraint propagation, intelligent backtracking and ordered searching techniques. 30 The strategy used is to assign atom values from the molecular formula to atoms of the substructure (node variables) until an assignment takes place that is not consistent with all the previous assignments, at which stage backtracking takes place, and another atom value is assigned to the preceding variable. What this means in plain terms is that a substructure is constructed, at which stage a new component is attached (see Fig.…”

Handling structured and ambiguous constraints in constraint satisfaction problems

“…In (Nuzillard 1995) the authors showed that a SGP can be considered as a constraint satisfaction problem (CSP). R esults in solving medium-sized real-life problems were reported.…”