With the absence of a notable T s effect on dissociation, we aimed to determine the barrier height and its distribution for the direct dissociation process (assuming a simplified 1D PES). Since both parallel and perpendicular momentum contribute similarly to overcoming the dissociation barrier, it is reasonable to assume that the barrier height distribution is consistent across all angles of incidence. Therefore, we used the measurements at normal incidence and nozzle temperature of 300 K to fit an S-shaped function for determining the barrier height and its distribution. Barrier height distribution is a convolution of various parameters, including beam energy distribution, surface temperature, the vibrational energy of molecules, the orientation of molecules in the molecular beam, and impact sites. Given our findings that surface temperature and vibrational energy have minimal influence on dissociation probability, the remaining parameters significantly contribute to the barrier height distribution. Knowing the energy spread of our incident beam, which ranged from 20% to 55% for T n varying from 300 K to 850 K, respectively (see SI-3), we can infer the contribution of orientation and impact sites on barrier height distribution. From the Sshaped fitting function, we obtained the parameters: A = 0.04, E 0 = 1.6 eV, and W 0 = 0.4 eV. After accounting for the energy spread in the molecular beam, the effective barrier width W 0 was determined to be 0.3 eV (see SI-7). To further understand the individual contribution of orientation and impact sites on the S 0 , it will be interesting to look into the results from simulations.