Topology and Geometry of Oxaceprol. The geometry and topology of Oxaceprol. Pharmacophore types shown in the 3 D structure are 1 = [L], 3 = [A - [#7H0]], 6 = [D - [OH], A - [O]],8 = [L], 9 = [A - [O]],10 = [N], 11 = [A - [O]], 12 = [D - [OH], A - [O]]. The geometry and topology of this compound is the basis for the exemplary fingerprints shown in Table 1. Note that multiple PPPs can be assigned to an atom: In this case atoms 6 and 12 have two valid PPPs.