# Tag Info

The method they are using seems to be looking at the separation between two different transitions to determine $B$. $J''$ denotes the lower energy state in a transition and $J'$ denotes the higher energy state. Here, you are looking at two different transitions: $$J_1'=4\to J_1''=3 \text{ with } \nu_{4\to 3}=\pu{15.365cm^-1}$$ J_2'=9\to J_2''=8 \text{ ...