Neural networks using the backpropagation algorithm can be applied to
quantitative structure-physical property relationship studies. Neural
networks can be trained with electrotopological indexes of monofunctio
nal compounds to predict the corresponding retention index data. These
networks can also be applied to the prediction of retention index dat
a of acyclic and cyclic monoterpenes and a mixed set of monosubstitute
d and terpene compounds. Predictions by neural networks are generally
in good agreement with predictions done by multilinear regression tech
niques. In the case of predicting retention index data of compounds fr
om a class not represented in the training data, neural networks show
strong deficiencies in comparison with multilinear regression methods.