Pharmacophore Fingerprint

The fingerprints (which are chemical descriptors) are constructed from sequences of histograms, each of these histograms have the same number of bars. (Each of these bars represent a descriptor cell.) The number of histograms is determined by the number of pharmacophore types (also often referred as features, properties). If the number of distinct pharmacophore features (for instance H-donor, H-acceptor, charge etc.) is n then the number of histograms is n*(n+1)/2.