Fig. 4From: PubChem atom environmentsAtom environment statistics. Number of unique atom environments with radius: a r = 0 (atom types), b r = 1; c r = 2; and d r = 3. Values are per fraction of the respective database, PubChem Substance (104,669,789 SIDs), and PubChem Compound (46,704,121 CIDs). Total fragment counts for r = 0,1,2,3 are: 8,135 atom types, 299,609, 5,453,889, and 26,988,962 atom environments, respectively, for Substance; and 1,583 atom types, 109,306, 4,559,587, and 25,115,177 atom environments, respectively, for Compound.Back to article page