A systematic manner to explore SARs and SMARts qualitatively and quantitatively is through the analysis of chemical space, also called chemical universe, a fundamental concept in chemoinformatics . The chemical space has been defined as a multi-dimensional descriptor space where the compounds can be located . Adding one or more biological activities to the chemical space gives rise to a so-called chemogenomics space , enabling the qualitative exploration or systematic and quantitative analysis of SARs or SMARts . Since the chemical space of a set of compounds strongly depends on the set of descriptors to define the multi-dimensional space, it has been suggested that multiple descriptors describe better compound data sets , giving rise to the concept of chemical multiverse .