16423
These rotational constants along with those of the ( 13 ) C , ( 15 ) N , and D1 species were used together with vibration - rotation constants calculated from a cubic force field calculated at the B3LYP / 6 - 311 + G ( 3df , 2pd ) level of theory to derive a semiexperimental equilibrium structure .
 Chemical: ( 13 ) C; Chemical: ( 15 ) N
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: ( 13 ) C; Chemical: ( 15 ) N