14563
Recent studies have also shown that the ( 011 ) surface is relatively easy for preparation in ultra - high vacuum ( UHV ) and that both the ( 110 ) and ( 011 ) surfaces could be precisely characterized using scanning tunneling microscopy ( STM ) .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None