7141
Parallel tempering molecular dynamics simulation suggests that the hydrogen bond distance variation at different temperatures / replicas is largely responsible for the ( 1 ) H ( N ) chemical shift temperature dependence , from which an empirical equation is proposed to predict the hydrogen bond thermal expansion coefficient , revealing responses of individual hydrogen bonds to temperature changes .
 Chemical: hydrogen; Chemical: ( 1 ) H ( N ); Chemical: hydrogen; 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: hydrogen; Chemical: ( 1 ) H ( N ); Chemical: hydrogen; Chemical: hydrogen