13877
Although the Fe - H distances are indistinguishable in the precursor , they differ by 0 . 2 A in [ H1 ] ( 0 ) .
 Chemical: Fe - H; Chemical: H1
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: Fe - H; Chemical: H1