We present the first angle resolved study of H-2 Molecules coming from a hydrogenated Si(100)-2 x 1 surface at 650 K exposed to a chopped hydrogen atomic beam under fixed incidence angle. We get an exceptionally wide angular distribution, which can be fitted by cos(n)O with n < 1. We interpret this new result by a non-activated pathway involving collision induced desorption and site-specific hot atom abstraction on two neighbor Si dimers inside a dimer row after passing through a transition state similar to the inter-dimer 4H reaction path, recently proposed in a H-2/Si(100)-2 x 1 system. (c) 2005 Elsevier B.V. All rights reserved.