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DFT calculations show that mercaptopropionic acid ( MPA ) and cysteine ( Cys ) exhibit characteristic binding configurations on TiO ( 2 ) surfaces .
 Chemical: mercaptopropionic acid; Chemical: MPA; Chemical: cysteine; Chemical: Cys; Chemical: TiO ( 2 )
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: mercaptopropionic acid; Chemical: MPA; Chemical: cysteine; Chemical: Cys; Chemical: TiO ( 2 )