24882
We investigate the topological surface state properties at various surface cleaves in the topological insulator Bi2Se3 , via first principles calculations and scanning tunneling microscopy / spectroscopy ( STM / STS ) .
 Chemical: Bi2Se3
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: Bi2Se3