21817
The bare tritungsten clusters are predicted to be triangular structures with D3h ( ( 3 ) A1 ' ) , C2v ( ( 2 ) A1 ) and D3h ( ( 1 ) A1 ' ) symmetry for W3 , W3 ( - ) and W3 ( 2 - ) , respectively .
 Chemical: tritungsten; Chemical: W3; Chemical: W3 ( - ); Chemical: W3 ( 2 - )
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: tritungsten, W3, W3 ( - ), W3 ( 2 - ) 
Answer:
 Chemical: tritungsten; Chemical: W3; Chemical: W3 ( - ); Chemical: W3 ( 2 - )