Structure-activity methods based on molecular descriptors that are a combination of structural information about the through-space and through-bond relationships between components of a molecule's structure and spectral data attributable to those components are disclosed. In some embodiments, a molecule is described by multiple sets of such descriptors to account for flexibility in the structure of the molecule. In a particularly disclosed embodiment, predicted 13C—13C COSY data and 13C—13C distance data are used as descriptors. Models of molecular properties may be established using the disclosed spectral data-activity methods and used to predict the properties of molecules.