The second statistically significant fragment is a pyzazine-like fragment, c1nc(C)cnc1NC (Figure ). The fragment is found in 45 molecules, and their mean oscillator strength is 0.471, which is the highest among the eight identified fragments. The third and fourth significant fragments are a triazole-like structure (4H-Triazol-4-ylmethanamine), and 1-acetylpyrrolidinelike structure, respectively. They both are contained in 26 molecules in the dataset and have oscillator strength over 0.35.