We performed molecular-dynamics simulation on the pair correlation function, mean-square displacement, and self-part intermediate scattering function for supercooled Liquid nitrogen dimers. Our simulation data showed that for the latter the orientational degree of freedom, if identified as a form of structural impediment, has the consequence of making more robust the structural arrest at decreasing temperature. This conclusion is consistent with the magnitude of the lambda parameter determined in conjunction with the idealized mode-coupling theory for the description of the dynamics of beta relaxation.