21361
In this study , we develop and apply a novel combination of all - atom molecular dynamics and coarse - grained ( CG ) analysis to characterize two important steps of the catalytic cycle of [ FeFe ] - hydrogenase .
 Chemical: [ FeFe ]
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: [ FeFe ]