The notion of using multiple structure representations to study the chemical space of compound data sets has been recently called "chemical multiverse" defined as "a group of multiple chemical spaces, each one defined by a given set of descriptors e. g., a group of "descriptor universes" . In this sense, a number of studies that use multiple descriptors to represent the chemical space of a compound data sets can be regarded as "chemical multiverses," as reviewed elsewhere . In a different approach, Chemical Library Networks have been recently proposed to combine and represent chemical space and study the diversity of large and ultra-large chemical libraries .