Examples for Structure Derivation

The query compound is considered as unknown that is, only infrared spectrum is used for prediction. The prediction of a molecule is performed by a search for the most similar descriptors in a binary descriptor database. The database contains compressed low-pass filtered D20 transformed RDF descriptors of 64 components each. The descriptors originally used for training (Cartesian RDF, 128 components) were compressed in the same way before the search process. 

FIGURE 6.5 The infrared spectrum of a query compound compressed by Hadamard transform for the prediction of benzene derivatives by a CPG neural networks. The spectrum exhibits some typical bands for aromatic systems and chlorine atoms. 

FIGURE 6.6 Benzene derivatives predicted by a CPG neural network (low-pass Z 2o Cartesian RDF, 128 components). The 2D images of the eight best matching structures from the descriptor database are shown together with the correlation coefficients between their descriptor and the one predicted from the neural network. 

Fignre6.7 and Fignre6.8 show another example of correct predictions for bicyclic componnds, displaying qnery infrared spectra and the eight best matching 

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