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.
@article{arxiv.2108.06257,
title = {Atomic structure of the continuous random network of amorphous C[(C6H4)2]2, PAF-1},
author = {Guanqun Cai and He Lin and Ziqiang Zhao and Jiaxun Liu and Anthony E Phillips and Thomas F Headen and Tristan G A Youngs and Yang Hai and Haolai Tian and Chunyong He and Yubin Ke and Juzhou Tao and Teng Ben and Martin T Dove},
journal= {arXiv preprint arXiv:2108.06257},
year = {2021}
}