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The CdA films , containing 2n + 1 layers , with integer n ranging from 0 to 4 , are surface - terminated identically by the methyl group but exhibit the thickness - dependent morphology .
 Chemical: CdA; Chemical: methyl
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: CdA; Chemical: methyl