11598
In this discussion , after looking at some of the experimental observations of halogen bonding , we address the origins of sigma holes , the factors that govern the magnitudes of their electrostatic potentials , and the properties of the resulting complexes with negative sites .
 Chemical: halogen
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
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Answer:
 Chemical: halogen