Increasing the reaction temperature appreciably raises the dissociation adsorption free energy barrier from 2.02 ± 0.12 eV at 700 K to 2.75 ± 0.09 eV at 1400 K, mainly because the gas phase has higher entropy than the adsorbed state. Laser-assisted associative desorption experiments have reported the barrier to be ~1.8 to 2.1 eV for samples with ~23 to 48 % nitrogen coverage. A recent quasi-classical simulation study based on DFT has determined that a barrier of 1.8 eV is consistent with scattering experiments. Calculated barriers using CFF-AIMD at 700 K (2.02 ± 0.12 eV) are in reasonable agreement with available experimental data within a few tenths of eV.