[{"from": "human", "value": "Given SMILES, write its poly dispersity index at room temperature and atmospheric pressure. ->  CC(S1)=CC2=C1C(OCC(CCCCCCCCCC)CCCCCCCC)=C(C=C(C3=CC=C(C4=CC=C(C5=CC=C(C)S5)C6=N[Se]N=C64)S3)S7)C7=C2OCC(CCCCCCCCCC)CCCCCCCC\n"}, {"from": "gpt", "value": " 2.1\n"}]