In silico screening of large databases of existing screening samples for the purpose of computer-aided drug design has made significant strides in the recent past, both in terms of the methodologies and software available and size and diversity of screening sample collections. Aggregated libraries on the order of 100 million on-the-shelf unique compounds are available in the commercial market 1 . Still, this MN-2 represents only a microscopically small fraction of the drug-like small-molecule space, which has been variously estimated to be on the order of 10 21 to 10 63 possible structures or even larger .