9771
A new crystallographic structure is described for Sudan I , revealing the presence of intramolecular hydrogen bonds and supramolecular interactions , such as the unconventional C - H . . . O hydrogen bond type , pi - stacking , and charge - dipole interactions .
 Chemical: Sudan I; Chemical: hydrogen; Chemical: C - H; Chemical: O; Chemical: hydrogen
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Sudan I; Chemical: hydrogen; Chemical: C - H; Chemical: O; Chemical: hydrogen