RRKM reaction rate calculations for the 1-to-2 H/D-shifts of (a) deuteronated anthracene, [D − C₁₄H₁₀]⁺ and (b) protonated, perdeuterated anthracene, [H − C₁₄D₁₀]⁺ from the 1-isomer to the 2-isomer, plotted as a function of the internal energy of the molecule in eV. In both (a) and (b), the black curves depict the hydrogen shifting rates and the red curves depict the D shifting rates. Dotted lines depict internal energies attained through IR (min. 2.7 eV) and UV (max. 4.7 eV) excitation.