  We demonstrate that the amorphous material PAF-1, C[(C6H4)2]2, forms a
continuous random network in which tetrahedral carbon sites are connected by
4,4'-biphenyl linkers. Experimental neutron total scattering measurements on
deuterated, hydrogenous, and null-scattering samples agree with molecular
dynamics simulations based on this model. From the MD model, we are able for
the first time to interrogate the atomistic structure. The small-angle
scattering is consistent with Porod scattering from particle surfaces, of the
form Q^{-4}, where Q is the scattering vector. We measure a distinct peak in
the scattering at Q = 0.45 {\AA}^{-1}, corresponding to the first sharp
diffraction peak in amorphous silica, which indicates the structural analogy
between these two amorphous tetrahedral networks.
