12658
The resulting torsional frequencies are found to be 18 . 8 and 15 . 9 cm ( - 1 ) for isomers a and b of OCS - CO ( 2 ) , respectively .
 Chemical: OCS; Chemical: CO ( 2 )
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: OCS; Chemical: CO ( 2 )